2-substituted tertiary carbinol derivative of 1,5-iminosugars

ABSTRACT

Novel 2-alkyl carbinol derivatives of deoxynojirimycin (DNJ) and the chemical synthesis of these derivatives and intermediates therefor from DNJ and their method of inhibiting lentiviruses are disclosed.

This is a division of application Ser. No. 07/861,058, filed Apr. 1,1992, now U.S. Pat. No. 5,258,518.

BACKGROUND OF THE INVENTION

This invention relates to novel 2-substituted tertiary carbinolderivatives of 1,5-dideoxy-1,5-imino-D-glucitol and, more particularly,to the chemical synthesis of these derivatives and intermediatestherefor, and to their method of inhibiting viruses such aslentiviruses.

1,5-dideoxy-1,5-imino-D-glucitol-(deoxynojirimycin or DNJ) and itsN-alkyl and O-acylated derivatives are known inhibitor of viruses suchas human immunodeficiency virus (HIV). See, e.g., U.S. Pat. Nos.4,849,430; 5,003,072; 5,030,638 and PCT Int'l. Appln. WO 87/03903.Several of these derivatives also are effective against other virusessuch as HSV and CMV as disclosed in U.S. Pat. No. 4,957,926. In somecases antiviral activity is enhanced by combination of the DNJderivative with other antiviral agents such as AZT as described in U.S.Pat. No. 5,011,829. Various of these DNJ derivative compounds also haveantihyperglycemic activity. See, e.g., U.S. Pat. Nos. 4,182,763,4,533,668 and 4,639,436.

Notwithstanding the foregoing, the search continues for the discoveryand novel synthesis of new and improved antiviral compounds.

BRIEF DESCRIPTION OF THE INVENTION

In accordance with the present invention, novel 2-substituted tertiarycarbinol derivatives of 1,5-dideoxy-1,5-imino-D-glucitol are provided.According to another embodiment of the invention, novel methods ofchemical synthesis of these DNJ derivatives and their intermediates areprovided. The novel DNJ derivatives and various of their intermediateshave useful antiviral activity as demonstrated against lentivirus.

The 2-substituted tertiary carbinol derivatives of1,5-dideoxy-1,5-imino-D-glucitol can be represented by the followinggeneral structural Formula I: ##STR1## wherein R₄ =an alkyl, vinyl,alkenyl, alkynyl, aryl, aralkyl, alkenylalkyl, alkynylalkyl or CH₂ Ysubstituent having from about 1 to 10 carbon atoms;

Y=OR', SR', NR'R', or N₃ ;

R'=H or CH₃ ; and

R=H or an alkyl, aralkyl, alkenylalkyl, alkynylalkyl, aralkenyl,aralkynyl or hydroxyalkyl substituent having about 1 to 18 carbon atoms,provided that no carbon unsaturated bond is directly attached tonitrogen.

In Formula I, the alkyl moieties in the R substituents preferably arestraight chain or branched alkyl groups or cycloalkyl groups whichpreferably have from one to about 8 carbon atoms, e.g., methyl, ethyl,propyl, isopropyl, n-butyl, iso-butyl, sec.-butyl. tert-butyl, pentyl,hexyl, heptyl, octyl, 2-ethylbutyl, 2-methylpentyl, cyclopentyl andcyclohexyl, and which can contain one or more heteroatoms, e.g. O, S, N.The alkyl moieties in the R₄ substituents preferably have from one toabout 4 carbon atoms, e.g., methyl, ethyl, isopropyl and sec.-butyl. Thecorresponding alkenyl moieties in Formula I are, e.g., ethenyl,propenyl, butenyl, pentenyl, hexenyl, and the corresponding alkynylmoieties are, e.g., ethynyl, propynyl, butynyl, pentynyl, hexynyl, andtheir alkyl-substituted derivatives, e.g. methylbutenyl andmethylbutynyl.

Also in Formula I, the aryl moieties in the R and R₄ substituentspreferably are phenyl and substituted phenyl, e.g., lower alkylphenylsuch as 2-methylphenyl and 2,4-dimethylphenyl; halophenyl such as2-chlorophenyl, 4-chlorophenyl, 2,4-dichlorophenyl, 2-bromophenyl,4-fluorophenyl, 2,4-difluoromethylphenyl and trifluoromethylphenyl;methoxyphenyl and nitrophenyl.

Preferred compounds of Formula I are the following:

    1,5-Dideoxy-1,5-imino-2-C-methyl-D-glucitol,

    1,5-Butylimino-1,5-dideoxy-2-C-methyl-D-glucitol,

    1,5-Dideoxy-1,5-(3-phenylpropylimino)-2-C-methyl-D-glucitol, and

    1,5-Dideoxy-1,5-(2-ethylbutylimino)-2-C-methyl-D-glucitol.

The novel synthesis of compounds of Formula I comprises thestereoselective addition of an organometallic reagent, e.g. a Grignardreagent, to the carbonyl at C-2. The substituent at C-3 stronglyinfluences the stereochemical configuration at C-2. The unambiguousassignment of absolute stereochemistry at C-2 in these novel compoundsand intermediates used in their preparation has been established by aseries of NMR tests including spin decoupling. For description of theseconventional techniques (e.g., NOESY and COSY), see e.g., Neuhaus andWilliamson, "The Nuclear Overhauser Effect in Structural andConformational Analysis," VCH Publishers, New York, 1989; and Martin andZektzer, "Two-Dimensional NMR Methods for Establishing MolecularConnectivity," VCH Publishers, New York, 1988.

In accordance with a preferred embodiment of the invention, thecompounds of Formula I can be chemically synthesized by the sequence ofreactions shown in the following Reaction Scheme A (or 2-part ReactionScheme B), in which the numbers in parentheses refer to the compoundsdefined by the generic formula shown above said numbers. R₁, R₂, R₃, R₅,X and W in Reaction Scheme A-B can be any alkyl or aryl group such asillustrated by the reactants and products described hereinafter.

In accordance with another aspect of the invention, novel pro-drugs ofthe antiviral compounds of Formula I are prepared by O-acylation oftheir free hydroxyl groups. ##STR2##

The foregoing Reaction Scheme A-B comprises the following generalreaction steps:

(a) The starting material, DNJ (1), is N-acylated with an acylatingagent to form an amide or carbamate derivative of DNJ (2);

(b) The hydroxyls at C-4 and C-6 are protected with a hydroxylprotecting agent by acetalization or ketalization to form an acetal orketal (3);

(c) The hydroxyl at C-2 is selectively protected by O-acylation with anacylating agent at C-2 to give novel intermediate (4);

(d) The hydroxyl at C-3 is protected by ether formation to produce thefully protected novel derivative (5);

(e) The protecting group at C-2 is selectively removed by cleavage ofester or carbonate to give novel product (6);

(f) The free hydroxyl group at C-2 is oxidized to give novel ketone (7);

(g) The stereoselective addition of the desired R₄ is carried out bynucleophilic addition at C-2 to form the novel 2-substituted tertiarycarbinol (8);

(h) The hydroxyl protecting group at C-3 is selectively removed bycleavage of ether to form novel product (9);

(i) The N-carbamate group is cleaved to give novel intermediate (10);

(j) The hydroxyl protecting group at C-4 and C-6 is removed by cleavageof acetal or ketal to give the novel intermediate (11);

(k) Intermediate (11) is N-alkylated to give the desired novel antiviral2-substituted tertiary carbinol derivatives of DNJ, viz. compounds (12).

(l) The free hydroxyl groups in the 2-substituted tertiary carbinolderivatives of DNJ (12) can be partially or fully 0-acylated to givenovel compounds (13).

The sequence of steps (h), (i), (j) and (k), involving cleavage ofvarious protecting groups to give intermediates (9), (10), (11) and(12), can be interchanged or combined.

Illustrative reaction conditions for carrying out the synthesis steps ofReaction Scheme A-B are as follows:

N-Acylation of DNJ (1) in step (a) can be carried out by conventionalN-acylation procedures well known to those skilled in the art. Suitablegeneral procedures for acylation of amines are described in U.S. Pat.No. 5,003,072; March, J. in Advanced Organic Chemistry, Wiley, New York,1985; Patai, S. (Ed.) in The Chemistry of Amides, Wiley, New York, 1970.For example, DNJ is N-acylated to form an amide, carbamate orthiocarbamate using a variety of reagents such as acyl halides (e.g.,acetyl chloride, propionyl bromide, benzoyl chloride or butyrylchloride), anhydrides (e.g., acetic anhydride, propionic anhydride orbutyric anhydride), chloroformates (e.g., methyl chloroformate, ethylchloroformate, vinyl chloroformate, benzyl chloroformate) ordicarbonates (e.g., di-tert-butyl dicarbonate). The reaction of DNJ withacyl halides is preferentially carried out in the presence of non-polar,aprotic solvents such as ethers (e.g., diethyl ether, tetrahydrofuran,dioxane, dimethoxyethane, dibutylether, tert-butyl methyl ether),chlorinated solvents (e.g., methylene chloride, chloroform, carbontetrachloride) or hydrocarbon solvents (e.g., benzene, toluene ).However, the reaction of DNJ (1) with anhydrides, chloroformates ordicarbonates is preferentially carried out by dissolving in one or moreof polar, protic solvents (such as water, methanol, ethanol) and in thepresence of a base (e.g, potassium carbonate, lithium carbonate, sodiumcarbonate, cesium carbonate, triethylamine, pyridine,4-dimethylaminopyridine, diisopropylethylamine,1,8-diazabicyclo[5,4,0]undec-7-ene). N-Acylation is preferentiallycarried out by reacting DNJ (1) with alkyl or aryl chloroformate insolvents such as DMF or aqueous sodium bicarbonate at 20°-50° C. to givethe product (2).

Protection of the hydroxyl groups at C-4 and C-6 in step (b) to giveacetal or ketal derivative (3) can be carried out by conventionalhydroxyl protection procedures such as those described, e.g., in U.S.Pat. No. 5,003,072 and in Green, T. W., Protective Groups in OrganicSynthesis, Wiley, New York, 1981, or 2d ed., 1991. The cyclic acetalsand ketals are formed by the reaction of 4,6-dihydroxy compound (2) withan aldehyde or a ketone in the presence of an acid catalyst.Illustrative carbonyl (or carbonyl equivalents such as dimethyl acetalor dimethyl ketal) compounds useful in this reaction are benzaldehyde,4-methoxybenzaldehyde, 2,4-dimethoxybenzaldehyde,4-dimethylaminobenzaldehyde, 2-nitrobenzaldehyde,2,2,2-trichloroacetaldehyde (chloral) and acetophenone. The acidcatalysts suitable for this reaction are, e.g., para-toluene sulfonicacid, cat. HCl, cat. sulfuric acid, FeCl₃, ZnCl₂, SnCl₂ and BF₃-etherate, and the reaction is carried out in the presence of aproticsolvents such as methylene chloride, 1,2-dimethoxyethane, dioxane,dimethylformamide, acetonitrile, dimethylacetamide or dimethylsulfoxide.Thus para-toluene sulfonic acid is added to a solution of benzaldehydedimethyl acetal in organic medium, e.g., dimethylformamide, and reactedwith N-acyl-DNJ (2) at 20°-65° C. to give the product (3).

The selective protection of hydroxy group at C-2 in compound (3) in step(c) can be carried out by reaction with O-acylation forming esters (suchas acetate, chloroacetate, dichloroacetate, trichloroacetate,methoxyacetate, phenoxyacetate, 4-chlorophenoxyacetate, isobutyrate,pivolate, benzoate, 4-phenylbenzoate, 4-methylbensoate,4-chlorobenzoate, 4-nitrobenzoate, and the like) and carbonates (such asmethyl, ethyl, 2,2,2-trichloroethyl, isobutyl, vinyl, allyl, phenyl,benzyl, 4-methoxybenzyl and the like) using acid chloride, anhydrides orchloroformates. The selective acylation at C-2 can be carried out byusing conventional acylation procedures such as described e.g., in U.S.Pat. No. 5,025,021. Two preferred methods are as follows:

Method A--Compound (3) is refluxed with dibutyltin oxide in solvents(such as benzene, toluene, xylene, methanol or ethanol and the like) toform a homogenous solution. The stannylene intermediate is then reactedat 0°-50° C. in the presence of a base (such as triethylamine, pyridine,4-dimethylaminopyridine, 1,8-diazabicyclo[5,4,0]undec-7-ene ordiisopropylethylamine) and an acylating agent (such as acetyl chloride,benzoyl chloride, pivaloyl chloride, chloroacetyl chloride, aceticanhydride, isobutyric anhydride, methyl chloroformate, ethylchloroformate, isobutylchlorofomate, phenyl chloroformate, benzylchloroformate and the like) to provide selective protection at C-2 andgive the novel intermediate (4).

Method B--A solution of compound (3) and tetrabutylammonium iodide in achlorinated solvent such as methylene chloride, 1,2-dichloroethane orcarbon tetrachloride is reacted with an acylating agent, e.g., benzoylchloride, under basic conditions, e.g., with potassium carbonate, sodiumcarbonate or cesium carbonate to provide 2-O-acyl protection selectivelyat C-2 and give the novel intermediate (4).

Protection of the hydroxyl group at C-3 in step (d) can be carried outby forming an ether (e.g., methoxymethyl, metylthiomethyl, benzyl,benzyloxymethyl, 2,2,2-trichloroethoxymethyl, 2-methoxyethoxymethyl(MEM), 2-(trimethylsilyl)ethoxymethyl (SEM), triethylsilyl,tert-butyldimethylsilyl (TBDMS), tert-butyldiphenylsilyl,triisopropylsilyl, isopropyldimethylsilyl, methyldiisopropylsilyl ormethyldi-tert-butylsilyl using conventional hydroxyl protectionprocedures (see, e.g., Green, T. W., Protective Groups in OrganicSynthesis, Wiley, New York, 1981, 2d ed., 1991). Thus the intermediatecompound (4) can be reacted with a protecting agent, e.g.,2-methoxyethoxymethyl chloride, 2-(trimethylsilyl)ethoxymethyl chloride,tert-butyldimethylsilyl trifluoromethnesulfonate or triisopropylsilyltrifluoromethnesulfonate to give the novel fully protected intermediate(5). This ether formation is preferably carried out in the presence of anon-polar, aprotic solvent (e.g., diethyl ether, tetrahydrofuran,dioxane, dimethoxyethane, dibutylether, tert-butyl methyl ether,methylene chloride, chloroform or carbon tetrachloride) using a base(such as triethylamine, pyridine, 4-dimethylaminopyridine,1,8-diazabicyclo[5,4,0]undec-7-ene or diisopropylethylamine) attemperature of 0°-50° C.

Selective removal of the protecting group (ester or carbonate) at C-2 instep (e) can be carried out by reaction of the intermediate (5) withtetrabutylammonium hydroxide in aqueous dioxane or with other bases,e.g., aqueous sodium hydroxide, aqueous potassium hydroxide, aqueouspotassium carbonate, aqueous lithium hydroxide, aqueous lithiumcarbonate, ammonium hydroxide or aqueous methylamine (with or withoutthe presence of organic solvents such as methanol, ethanol or dioxane)to give the novel intermediate (6). The acetate group at C-2 can also beremoved by reaction with potassium cyanide or sodium cyanide or byenzymatic reaction with lipases. Various of the carbonates at C-2 canalso be removed by special conditions. For example, 2,2,2-trichloroethylcarbonate can be cleaved by treatment with zinc in methanol.

Since the rest of the molecule is fully protected, the oxidation of thesecondary alcohol in (6) can be successfully carried out in step (f) byreaction with a variety of oxidizing agents [see, e.g., March, J. inAdvanced Organic Chemistry, Wiley, New York, 1985; House, H. O. inModern Synthetic Reactions, Benzamin Publishing Co., Massachusetts,1972; Augustine, R. L. in Oxidations - Techniques and Applications inOrganic Synthesis, Dekker, New York, 1969; W. P. Griffith and S. M.Levy, Aldrichchimica Acta 23, 13 (1990); R. M. Moriarty and O. Prakash,J. Org. Chem. 50, 151, (1985); A. Mancuso, D. Swern, Synthesis 165,(1981); S. Czernecki, C. Georgoulus, C. L. Stevens and K. Vijayakantam,Tetrahedron Lett. 26, 1699 (1985); J. Herscovici, M. J. Egra and K.Antonakis, J. Chem. Soc. Perkin Trans 1, 1967 (1982); E. J. Corey, E.Barrette and P. Magriotis, Tetrahedron Lett. 26, 5855 (1985); and H.Tomioka, K. Oshima and H. Nozaki, Tetrahedron Lett. 23, 539 (1982)].Illustrative of the reagents suitable for oxidation of the C-2 hydroxylin compound (6) are pyridinium chlorochromate (with or without additivessuch as sodium acetate, celite, alumina or molecular sieves), pyridiniumdichromate, chromium trioxide/pyridine, 2,2'-bipyridiniumchlorochromate, cyclic chromate ester [E. J. Corey, E. Barrette and P.Magriotis, Tetrahedron Lett. 26, 5855 (1985)], RuCl₂ (PPh₃)₃-tert-BuOOH, silver carbonate on celite, cerium (IV) ammonium nitrate(with or without sodium bromate), tetra-n-propylammonium perruthenateand activated dimethyl sulfoxide reagents (using DMSO and one of theelectrophilic reagents such as acetic anhydride, trifluoroaceticanhydride [TFAA], oxalyl chloride, trifluorosulfonic anhydride ordicyclohexylcarbodiimide). Formation of the novel carbonyl compound (7)is preferentially carried out by oxidation of the hydroxyl group at C-2in (6) with trifluoroacetic anhydride in dimethylsulfoxide (DMSO) usingmethylene choride as solvent at -70° to 0° C.

The introduction of alkyl (C₁ -C₄), vinyl, alkynyl, aryl, aralkyl, andother R₄ groups at C-2 in compound (8) in step (g) can be achieved bystereoselective addition of organometallic reagents (R₄ M) to the 2-ketoderivative (7) using conventional procedures (see, e.g., E. C. Ashby andJ. T. Laemmle, Chemical Reviews, 75, 521 (1975); K. Maruoka, Y. Araki,and H. Yamamoto, Tetrahedron Lett. 29, 3101 (1988); and K. Maruoka, T.Itoh, and H. Yamamoto, J. Am. Chem. Soc 107, 4576 (1985)]. For example,2-substituted tertiary carbinol derivatives (8) can be prepared byreaction of carbonyl compound (7) with Grignard reagents (e.g.,methylmagnesium chloride, methylmagnesium bromide, ethylmagnesiumbromide, isobutylmagnesium bromide, phenylmagnesium bromide,vinylmagnesium bromide or allylmagnesium bromide) in aprotic, non-polarsolvent (e.g., diethyl ether, tetrahydrofuran, dioxane, dimethoxyethane,dibutylether, tert-butyl methyl ether or benzene) at -70° to 20° C.Other organometallic reagents such as methyl lithium, lithium acetylide,sodium acetylide, ethylenediamine complex, dimethyl magnesium, trimethylaluminum, organozinc and organocadmium reagents obtained by addition ofGrignard reagents (R₄ MgCl) with zinc and cadmium halides, ate complexessuch as MeLi-Me₂ CuLi, LiMg(CH₃)₂, LiAl(i-C₄ H₉)₃ CH₃ and LiAl(CH₃)₄,can also be used to give the addition product (8).

The protecting group at C-3 in compound (8) is then removed in step (h)by appropriate selection of reagents to give the novel compound (9). Forexample, trialkylsilyl ethers and SEM ether in (8) can be removed byreagents carrying a fluoride source, such as tetrabutylammmoniumfluoride, CsF, terabutylammonium chtoride/KF, LiBF₄ or Ph₃ C⁺ BF₄ ⁻ orPyridine+HF to give (9). Methylthiomethyl ether can preferably becleaved with mercuric chloride or silver nitrate. Similarly,2,2,2-trichloromethoxymethyl ether can be cleaved by heating with Zn-Cuor Zn-Ag in methanol. Benzyl, substituted benzyl or benzyloxymethylethers can preferably be removed by catalytic hydrogenation procedures(using H₂, Pd/C in solvents such as ethanol, methanol, isopropanol andtetrahydrofuran). This catalytic hydrogenation procedure to remove thebenzyl ether is further useful because it simultaneously removes theN-protecting carbobenzoxy group from the compound (8) (W=OCH₂ Ph) andyields the novel intermediate(10) directly. If the hydroxyl group at C-3is protected as methoxymethyl or 2-methoxyethoxyethyl ether, it canpreferably be removed by aqueous acid (80% AcOH) or Lewis acid catalyzedcleavage (using ZnBr₂, TiCl₄ or HBF₄) after the carbamate hydrolysis (ofN-1) or the reduction (of amide at N-1 to the corresponding tertiaryamine) of compound (8).

The nitrogen protecting carbamate group in compound (9) can be easilyremoved in step (i) by base hydrolysis at temperature of 40° to 100° C.to give the novel compound (10). Illustrative bases suitable for thisreaction are aqueous sodium hydroxide, lithium hydroxide or potassiumhydroxide with or without the presence of organic solvents such asmethanol, ethanol, ethylene glycol and dioxane. The carbamates can alsobe cleaved by other reagents such as sulfur nucleophiles (e.g., sodiumthiomethoxide and lithium thiopropoxide) or iodotrimethylsilane. Benzylor substituted benzyl carbamates can be removed by base hydrolysis asmentioned above or by catalytic hydrogenation procedures, e.g. H₂ andPd/C or H₂ and Pd black.

The acetal or ketal group from the intermediate (10) can be removed instep (j) to give the novel intermediate (11) by using the followingconditions elaborated for the individual group. For example, thecleavage of benzylidene group in (10) can preferably be carried out byusing transfer hydrogenation in the presence of hydrogen donors such ascyclohexene or 1,4-cyclohexadiene. Thus, the benzylidene intermediate(10) is refluxed with Pd(OH)₂ in ethanol and cyclohexene to give thenovel intermediate (11). The benzylidine group in (10) can similarly beremoved by using metals (such as Li, Na or K) and liquid ammonia at -70°to -30° C. to give (11). The benzylidene acetal can also be cleavedusing N-bromosuccinimide and BaCO₃ (or CaCO₃) in carbon tetrachloride orby electrochemical reduction. 2,2,2-Trichloroethylidine acetal ispreferably cleaved by catalytic reduction (H₂, Raney Ni) using aqueoussodium hydroxide and ethanol. Alternately, the intermediate (9) (R₁ =Ph,X=H, W=OCH₂ Ph) can be directly converted to (11) using either transferhydrogenation [Pd(OH)₂, cyclohexene] or Na/ammonia reduction. Similarly,the preferred intermediate (25) (in generic formula 8, R₃ =CH₂ Ph, R₁=Ph, X=H, W=OCH₂ Ph) can also be converted to (11) in one step sequenceusing transfer hydrogenation or metal/ammonia reduction. ##STR3##

N-Alkylation of intermediate (11) can be carried out in step (k) byreductive alkylation procedures using NaCNBH₃, NaBH₄, and alkylaldehydeor by catalytic hydrogenation procedures such as described, e.g., inU.S. Pat. Nos. 4,182,763; 4,639,436; 5,003,072; and 5,003,638. Forexample, the N-alkylation can be carried out by reacting intermediate(11) with an appropriate alkylaldehyde in the presence of a hydrogendonor reducing agent, e.g., catalytically activated hydrogen.Hydrogenation in the presence of a noble metal catalyst, e.g.,palladium, at elevated pressure and temperature in methanol solventmedium is suitable. Appropriate alkylaldehydes for preparing thecorresponding N-alkyl derivative compounds (12) are, e.g., n-propanal,n-butanal, n-pentanal, n-hexanal, n-heptanal and n-octanal. Thus,reaction of an aldehyde having an alkyl moiety corresponding to thedesired R in Formula I with Pd on carbon in aqueous ethanol and THF issuitable procedure. Preferred aldehydes for this reaction are, e.g.,butyraldehyde, 3-phenylpropionaldehyde and 2-ethylbutyraldehyde toprepare novel antiviral compounds (XVIA), (XVIB) and (XVIC),respectively.

Alternatively, N-alkylation can be achieved by reacting intermediate(11) with alkylhalide such as benzyl bromide, bromobutane, bromohexane,iodomethane and the like in the presence of a base such astriethylamine, pyridine and diisopropylethylamine. Suitable solvents forthe reaction are, e.g., DMF, dimethylacetamide, dimethylsulfoxide andpyridine.

When the nitrogen in DNJ (1) is acylated as an amide [intermediate (2),W=alkyl, aralkyl], the sequence to target 2-substituted tertiarycarbinol derivatives proceeds as shown in Reaction Scheme A-B until theisolation of intermediate (9) (W=alkyl, aralkyl). The sequence is thenmodified as illustrated in Reaction Scheme C. ##STR4## The acetal orketal group from compound (9) is first removed following the conditionsillustrated for the synthesis of compound (11). The amide in thecompound (14) so obtained is then reduced to alkyl derivative (12A, R₆=CH₂ R) using reagents such as lithium aluminum hydride orborane-dimethyl sulfide complex. The novel intermediate (14) can also beprepared from the 2-alkyl carbinol derivative (11) by direct acylationusing acyl halide (e.g., acetyl chloride, propionyl bromide, butyrylchloride or benzoyl chloride or anhydrides, e.g., acetic anhydride,propionic anhydride or butyric anhydride). The reaction of compound (11)with acyl halides is preferentially carried out in the presence ofnon-polar, aprotic solvents such as ethers, e.g., diethyl ether,tetrahydrofuran, dioxane, dimethoxyethane, dibutylether, tert-butylmethyl ether, or chlorinated solvents e.g., methylene chloride,chloroform and carbon tetrachloride, or hydrocarbon solvents, e.g.,benzene and toluene. However, the reaction of (11) with anhydrides ispreferentially carried out by dissolving in one or more of polar, proticsolvents such as water, methanol or ethanol and in the presence of base,e.g, potassium carbonate, lithium carbonate, sodium carbonate, cesiumcarbonate, triethylamine, pyridine, 4-dimethylaminopyridine,diisopropylethylamine or 1,8-diazabicyclo[5,4,0]undec-7-ene].Alternately, the compound (9) is reduced first (preferably withborane-dimethyl sulfide complex) to give the intermediate (15) which isthen subjected to deacetalization/deketalization as illustrated above togive the compound (12A).

The compound (12) in Reaction Scheme A-B can be O-acylated (partially orfully) to give the novel compound (13) using conventional acylationprocedures for acylation well known to those skilled in the art.Illustrative suitable general procedures for acylation of hydroxylgroups are described in U.S. Pat. No. 5,003,072; March, J. in AdvancedOrganic Chemistry, Wiley, New York, 1985; Green, T. W., ProtectiveGroups in Organic Synthesis, Wiley, New York, 1981, 2d ed., 1991. Forexample, the compound (12) can be O-acylated to form ester or carbonateusing a variety of reagents such as acyl halides, e.g., acetyl chlorideand propionyl bromide, pivaloyl chloride, benzoyl chloride and butyrylchloride, or anhydrides, e.g., acetic anhydride, propionic anhydride andbutyric anhydride, or chloroformates, e.g., methyl chloroformate, ethylchloroformate, vinyl chloroformate, phenyl chloroformate and benzylchloroformate. The reaction of compound (12) with the acylating agent ispreferentially carried out in the presence of a base (such astriethylamine, pyridine, 4-dimethylaminopyridine, diisopropylethylamineor 1,8-diazabicyclo[5,4,0]undec-7-ene]. The reaction can be carried outusing the base as a solvent or having additional co-solvent, e.g.,diethyl ether, tetrahydrofuran, dioxane, dimethoxyethane, dibutylether,tert-butyl methyl ether, methylene chloride, chloroform, carbontetrachloride, benzene or toluene. This reaction is preferably becarried out at 20° to 90° C.

In the synthesis of preferred novel compounds of Formula I according tothe steps of the general Reaction Scheme A-B, the preferred reactionconditions are set forth in the following Reaction Schemes D, E and F.Synthesis of the 2-keto DNJ analogs VIIA to VIID from the starting DNJ(I) in steps (a) through (f) is set forth in Reaction Scheme D. Thestereoselective Grignard addition to the 2-keto DNJ analogs VIIA to VIIDto produce the 2-substituted tertiary carbinol intermediates VIIIA toXIIB in step (g) is set forth in Reaction Scheme E. The synthesis of the2-substituted tertiary carbinol derivatives of DNJ, compounds XVIA toXVIC, from the 2-substituted tertiary carbinol intermediate XIA in steps(h) to (k) is set forth in Reaction Scheme F. The compound XVIA isesterified to give the pro-drugs XVIIIA to XVIIIC. The intermediate XVis acylated to XVIIA and XVIIB which are reduced to novel antiviralcompound 12A of Reaction Scheme C. ##STR5##

    __________________________________________________________________________    Scheme E: Nucleophilic Additions to 2-Ketone                                                              Diastereomeric Ratio                                                                        Chem. Yield                         Compound (R.sub.3)                                                                           Reagent                                                                              R.sub.4                                                                             of products (A/B)                                                                           (%)                                 __________________________________________________________________________     ##STR6##      MeMgX  Me    VIIIA/VIIIB = <15/85                                                                        VIIIB = 62%                          ##STR7##      Me.sub.3 SiCH.sub.2 Li CeCl.sub.3                                                    CH.sub.2 SiMe.sub.3                                                                 IXA/IXB = <10/90                                                                            IXB = 43%                            ##STR8##      MeMgX  Me    XA/XB = 33/67 XA = 21% XB = 43%                    ##STR9##      MeMgX  Me    XIA/XIB = 92/8                                                                              XIA = 68% XIB = 5.4%                Me             MeMgX  Me    XIIA/XIIB = 93/7                                                                            XIIA = 54%                                                                    XIIB = 4%                           __________________________________________________________________________     ##STR10##

Compounds of the following two structures can be synthesized byfollowing the sequence of reaction steps and using the reactionconditions shown in Reaction Scheme F: ##STR11##

In the above formulas, alkyl preferably is propyl as in compounds(XVIIA) and (XVIIB) of Reaction Scheme F; and acyl preferably is butyrylas in compounds (XVIIIA), (XVIIIB) and (XVIIIC) of Reaction Scheme F.

In accordance with another embodiment of the invention, formation of the2-substituted tertiary carbinols from the 2-keto derivative (7) can becarried out by alternate methods that involve elaboration of an olefinor opening of an epoxide. This method is illustrated by the followingReaction Scheme G: ##STR12##

Reaction Scheme G comprises the following general reaction steps:

The ketone (7) is converted to novel olefinic compound (16). Thisconversion of compound (7) to the olefinic compound (16) can be achievedby a variety of methodologies such as by Wittig or modified Wittigolefination [see e.g., P. J. Murphy, J. Brennan, Chem. Soc Rev. 17, 1,(1988)], using Tebbe's reagent [F. N. Tebbe, G. W. Parshall and G. S.Reddy, J. Am. Chem. Soc. 100, 3611, (1978)] or other titanium basedreagents [e.g., L. Clawson, S. L. Buchwald and R. H. Grubbs, TetrahedronLett. 25, 5733, (1984)] or zirconium promoted olefination [J. M. Tour,P. V. Bedworth and R. Wu, Tetrahedron Lett 30, 3927, (1989)].

Olefinic intermediate (16) is reacted with 3-chloroperbenzoic acid(MCPBA) in methylene chloride at room temperature to form the novelepoxide intermediate derivative (17). The epoxidation of the olefin cansimilarly be achieved by a number of other reagents such asdimethyldioxirane, peroxy acids [see, e.g., Rebeck et al. J. Org. Chem.51, 1649 (1986)], Sharpless epoxidations using t-butylhydroperoxide[see, e.g., Katsuki and Sharpless, J. Am. Chem. Soc. 102, 5974 (1980);Ibid, Vol. 109, 5675 (1987); Wang and Zhou, Tetrahedron 43, 2935 (1987);Finn and Sharpless, J. Am. Chem. Soc. 113, 113 (1991)]; andsulfamyloxaziridines (Davis et al., Tetrahedron Lett. 27, 5079 (1986)].

The ketone (7) can also be converted to the epoxide directly by usingdimethyloxosulfonium methylide or dimethylsulfonium methylide [see,e.g., E. J. Corey and M. Chaykovsky, J. Am. Chem. Soc. 87, 1353 (1965)].

Both the olefin (16) and the epoxide (17) are novel and usefulintermediates for the synthesis of variety of 2-substitutedtert-carbinol derivatives represented in Formula I. For example, olefin(16) on treatment with osmium tetroxide (Reaction Scheme G) gives thediol (18), and the primary alcohol in (18) is alkylated with base (e.g.,triethylamine) and alkyl halide (C₁ -C₄) to give the useful intermediate(19). The useful epoxide intermediate (17) can be opened with a varietyof nucleophiles (Y) such as hydride, azide, thioalkyl and thioaryl (SR';R'=H, methyl, phenyl), and amine (NR'R'; R'=H, methyl) to give theintermediate (20). The 2-azidomethyl derivative of compound (19) (Y=N₃)can also be elaborated to 2-aminomethyl (Y=NH₂) and 2-alkylaminomethyl(Y=NR'R') derivatives. Both the intermediates (19 & 20) can then beelaborated to the fully deprotected compounds represented by structure(21) using the methodologies discussed in Reaction Scheme B for thesynthesis of (12).

The preferred conditions used for the synthesis of olefin (16) andepoxide (17) are shown in Reaction Scheme H. ##STR13## The ketone VIICis reacted with trimethylsilylmethyllithium to give the addition productIXB. The acetonitrile solution of compound IXB or XIX is refluxed with afluoride source such as tetrabutylammonium fluoride to give the novelolefinic intermediate XXA. The hydroxyl group at C-3 in XXA isreprotected using trialkylsilyl (e.g., tert-butyldimethylsilyl) to givethe novel olefin XXB. Epoxidation of the olefin (XXB) using3-chloroperbenzoic acid gives the diastereomeric mixture of epoxides(XXI & XXII) in ratio of 20/80. The lithium aluminum hydride reductionof the epoxides XXI & XXII gives the 2-methyl-tert-carbinol derivativesXXIII & XXIV, respectively.

The intermediate (4) of Reaction Scheme A-B can also be used for thesynthesis of 3-substituted ether (R₈ =C₁ -C₆) or 3-substitutedtert-carbinol derivatives (R₇ =R₄) as shown in Reaction Scheme I. Theintermediates VD and VID of Reaction Scheme D are useful substrates forthe synthesis of compounds (5) and (22) shown in Reaction Scheme I.##STR14##

In standard in vitro tests, the novel compounds of the invention weredemonstrated to inhibit HIV-1. These tests involved plating ofsusceptible human host cells which are syncytium-sensitive with andwithout virus in microculture plates, adding various concentrations ofthe test compound, incubating the plates for 9 days (during which timeinfected, non-drug treated control cells are largely or totallydestroyed by the virus), and then determining the number of remainingviable cells using a colorimetric endpoint.

Potential use against the AIDS virus also is shown by the inhibitoryactivity of these compounds against visna virus in a conventional plaquereduction assay. Visna virus, a lentivirus genetically very similar tothe AIDS virus, is pathogenic for sheep and goats. See Sonigo et al.,Cell 42, 369-382 (1985); Haase, Nature 322, 130-136 (1986). Inhibitionof visna virus replication in vitro as a useful model for humanimmunodeficiency virus (HIV) and its inhibition by test compounds hasbeen described by Frank et al., Antimicrobial Agents and Chemotherapy31(9), 1369-1374 (1987).

DETAILED DESCRIPTION OF THE INVENTION

The following examples will further illustrate the invention although itwill be understood that the invention is not limited to these specificexamples or the details disclosed therein.

EXAMPLE 1 Preparation of1,5-dideoxy-1,5-[{(phenylmethoxy)carbonyl}imino]-D-glucitol (II)

To a stirred solution of 1-deoxynojirimycin (100 g, 0.61 mol) insaturated aqueous sodium bicarbonate (1000 ml), benzyl chloroformate(95%, 121 g, 0.67 mol) was added dropwise at room temperature. Afterstirring at room temperature for 18 hr, the solution was extracted oncewith methylene chloride (300 ml) to remove any unreacted benzylchloroformate. The aqueous layer was then extracted several times withethyl acetate to give a total of 2.5-3 liters of the extract. Theorganic layer was then dried (Na₂ SO₄), filtered and concentrated togive a white solid (98 57 g, 54%), mp 101°-2° C. Anal calcd. for C₁₄ H₁₉NO₆ : C, 56.56, H, 6.44, N, 4.71. Found: C, 56.33, H, 6.38, N, 4.58. ¹ HNMR (CD₃ OD) 7.2-7.4 (m, 5H), 5.15 (s, 2H), 4.23 (br m, 1H), 4.05 (br d,J=8 Hz, 1H), 3.87 (dd, J=6, 4 Hz, 1H), 3.78-3.85 (m, 2H), 3.70-3.78 (m,2H), 3.45 (br d, J=8 Hz, 1H).

EXAMPLE 2 Preparation of1,5-dideoxy-1,5-[{(phenylmethoxy)carbonyl}imino]-4,6-O-(R-phenylmethylene)-D-glucitol(III)

A mixture of (II) (98.5 g, 0.33 mol), benzaldehyde dimethyl acetal (65.5g, 0.43 mol) and p-toluenesulfonic acid (1 g) in a round bottom flaskwas dissolved in dimethlformamide (400 ml). The flask was connected to awater aspirator and the reaction was heated to 60°-65° C. for 4 hr. Thereaction mixture was cooled to room temperature and poured into stirredice-water (1200 ml) containing sodium bicarbonate (14 g). The whitesolid formed was filtered, washed with cold water and dried.Recrystallization using hexane/ethyl acetate gave III (96.2 g, 54%) aspure white solid, mp 147°-48° C. Anal calcd. for C₂₁ H₂₃ NO₆ : C, 65.44,H, 6.02, N, 3.63. Found: C, 65.15, H, 5.93, N, 3.49. ¹ H NMR (CD₃ OD)7.28-7.53 (m, 10H), 5.61 (s, 1H), 5.14 (s, 2H), 4.77 (dd, J =11, 4.6 Hz,1H), 4.38 (t, J=11 Hz, 1H), 4.16 (dd, J =13.4, 4.2 Hz, 1H), 3.5-3.7(complex m, 3H), 3.35 (ddd, J=11, 11, 4.6 Hz), 2.97 (dd, J=13.4, 9.3 Hz,1H).

EXAMPLE 3 Preparation of1,5-dideoxy-1,5-[{(phenylmethoxy)carbonyl}imino]-4,6-O-(R-phenylmethylene)-D-glucitol,2-benzoate (IV)

Method A (Using Di-n-butyltin oxide):

A suspension of III (25 g, 64.9 mmol), dibutyltin oxide (98%, 17 g, 66.9mmol) in toluene (300 ml) was heated to reflux with azeotropic removalof water for 16 hr, whereupon a homogeneous solution resulted. Thereaction solution was cooled to room temperature and triethylamine (10.9ml, 77.5 mmol) and benzoyl chloride (7.7 ml, 67.5 mmol)were added. Afterstirring at room temperature for 24 hr, the reaction was diluted withaqueous solution of saturated sodium bicarbonate. The aqueous layer wasextracted with ethyl acetate (3×800 ml). The combined organic extractswere washed with 1N hydrochloric acid, water and brine. The organiclayer was dried (MgSO₄) and concentrated and the crude product waspurified using column chromatography (silica gel, hexane/ethyl acetate7/3) to give IV (21.52 g, 68%), DSC (mp) 120° C. Anal calcd for C₂₈ H₂₇NO₇ :

C, 68.70, H, 5.55, N, 2.86. Found: C, 68.17, H, 5.63, N, 2.75. 1H NMR(CDCl₃) 7.96 (d, J=8 Hz, 2H), 7.52 (t, J=8 Hz, 1H), 7.48 (m, 2H), 7.36(t, J=8 Hz, 2H), 7.30 (complex m, 8H), 5.51 (s, 1H), 5.07 (s, 2H), 5.05(m, 1H), 4.82 (dd, J=11, 5 Hz, 1H), 4.1(dd, J=11, 10 Hz, 1H), 4.04 (dd,J=14, 3 Hz, 1H), 3.88 (dd, J=8, 6 Hz, 1H), 3.73 (dd, J=10, 8 Hz, 1H),3.65 (brs, 1H), 3.42 (td, J=10, 5 Hz, 1H), 3.38 (dd, J=14, 7 Hz, 1H).

Method B (Using Tetrabutylammonium iodide):

To a suspension of III (1g, 2.6 mmol) in methylene chloride (20 ml),tetrabutylammonium iodide (960 mg, 2.6 mol) was added, whereupon ahomogenous solution resulted. Anhydrous potassium carbonate (972 mg, 5.2mmol) was added to the reaction and was followed by addition of benzoylchloride (0.3 ml, 2.6 mmol). After stirring at room temperature for 48hr, the reaction mixture was filtered and the residue was washed withmore methylene chloride. The combined organic filterates were washedwith water and dried (MgSO₄). After concentration, the crude (2.38 g)was chromatographed (silica gel, hexane/ethyl acetate 7/3) to give IV(810 mg, 64%) identical to the product of Method A.

EXAMPLE 4 Preparation of1,5-dideoxy-1,5-[{(phenylmethoxy)carbonyl}imino]-4,6-O-(R-phenylmethylene)-3-O-[{2-(methoxy)ethoxy}methyl]-D-glucitol,2-benzoate (VA)

To a homogenous solution of IV (1g, 2.04 mmol) in methylene chloride (20ml), N,N-diisopropylethylamine (99%, 2 ml, 12.27 mmol) and2-methoxyethoxymethyl chloride (1.4 ml, 12.27 mmol) were added. Afterstirring at room temperature for 24 hr, the reaction mixture was dilutedwith methylene chloride (700 ml) and washed with water and brine. Afterdrying (MgSO₄) and filteration, the organic solvent was removed and thecrude (1.47 g) chromatographed (silica gel, hexane/ethyl acetate 1/1) togive pure VA (1.15 g, 98%), DSC (mp) 109° C., Anal. calcd. for C₃₂ H₃₅NO₉ 0.3H₂ O: C, 65.92, H, 6.15, N, 2.40. Found: C, 65.81, H, 6.09, N,2.48.

EXAMPLE 5 Preparation of1,5-dideoxy-1,5-]{(phenylmethoxy)carbonyl}imino]-4,6-O-(R-phenylmethylene)-3-O-[{2-(trimethylsilyl)ethoxy]methyl]-D-glucitol,2-benzoate (VB)

To a homogenous solution of IV (35 g, 0.07 mol) in methylene chloride(450 ml), N,N-diisopropylethylamine (99%, 100 ml, 0.57 mol) and2-(trimethylsilyl)ethoxymethyl chloride (74.2 ml, 0.42 mol) were added.After stirring at room temperature for 24 hr, the reaction mixture wasdiluted with methylene chloride (700 ml) and washed with water andbrine. After drying (MgSO₄) and filteration, the organic solvent wasremoved to give VB (60.8 g) as thick orange liquid and was used in thenext step without further purification. ¹ H NMR (CDCl₃) 8.19 (d, J=8Hz,2H), 7.4-7.8 (complex band, 14H), 5.78 (s, 1H), 5.4 (m, 1H), 5.26 (s,2H), 5.08 (m, 1H), 5.07 (s, 2H), 4.1-4.35 (complex band, 4H), 3.65-3.9(complex band, 4H), 0.94 (m, 2H), 0.00 (s, 9H).

EXAMPLE 6 Preparation of1,5-dideoxy-1,5-[{(phenylmethoxy)carbonyl}imino]-4,6-O-(R-phenylmethylene)-3-O-[{2-{(1,1-dimethylethyl)dimethylsilyl}]-D-glucitol,2-benzoate (VC)

To a homogenous solution of IV (12 g, 24.5 mmol) in methylene chloride(200 ml), N,N-diisopropylethylamine (99%, 12.6 ml, 73.5 mmol) andtert-butyldimethylsilyl trifluoromethanesulfonate (11.3 ml, 49 mmol)were added. After stirring at room temperature for 2 hr, the reactionmixture was diluted with methylene chloride (700 ml) and washed withaqueous sodium bicarbonate, water and brine. After drying (MgSO₄) andfilteration, the organic solvent was removed and the crude (19 g)chromatographed (silica gel, hexane/ethyl acetate 8/2) to give VC (14.3g, 97%) as thick liquid. ¹ H NMR (CDCl₃) 8.02 (d, J=8Hz, 2H), 7.57 (t,J=8 Hz, 1H), 7.52 (m, 2H), 7.43 (t, J=8 Hz, 2H), 7.37 (m, 2H), 7.30 (m,6H), 5.58 (s, 1H), 5.14 (ddd, J=7, 5, 3 Hz, 1H), 5.08 (s, 2H), 4.89 (dd,J=11, 5 Hz, 1H), 4.16 (dd, J=11, 10 Hz, 1H), 4.03 (dd, J=14, 3 Hz, 1H),3.98 (dd, J=8, 5 Hz, 1H), 3.84 (dd, J=10, 8 Hz, 1H), 3.55 (td, J=10, 5Hz, 1H), 3.55 (dd, J=14, 7 Hz, 1H), 0.79 (s, 9H), 0.02 (s, 3H), 00.0 (s,3H).

EXAMPLE 7 Preparation of1,5-dideoxy-1,5-[{(phenylmethoxy)carbonyl}imino]-4,6-O-(R-phenylmethylene)-3-O-methyl-D-glucitol,2-benzoate (VD)

To a homogenous solution of IV (1.08 g, 1.82 mmol) in dimethylacetamide(20 ml) at 0° C., sodium hydride (182 mg, 60% dispersion in mineral oil,4.55 mmol) was added. After stirring for 20 min, iodomethane (570 μl,9.1 mmol) was injected in and the mixture was stirred for 4 hr. Thereaction was quenched with drops of acetic acid and diluted with water(100 ml). The crude mixture was extracted with methylene chloride(2×300) and the organic layer was washed with brine. After drying(MgSO₄) and filtration, the organic solvent was removed and the crude(1.18 g) chromatographed (silica gel, hexane/ethyl acetate 1/1) to giveVD (410 mg, 45%) as white solid, DSC (mp) 130° C., Anal. calcd. for C₂₉H₂₉ NO₇ 0.2H₂ O: C, 68.68, H, 5.84, N, 2.76 Found C, 68.60, H, 5.89, N,2.72.

EXAMPLE 8 Preparation of1,5-dideoxy-1,5-[{(phenylmethoxy)carbonyl}imino]-4,6-O-(R-phenylmethylene)-3-O-[{2-(methoxy)ethoxy}methyl]-D-glucitol(VIA)

To a solution of VA (12.91 g, 22 mmol) in dioxane (400 ml) andtetrabutylammonium hydroxide (30 ml of 40% aqueous solution diluted to200 ml) was added. After stirring at room temperature for 5 hr, thereaction was neutralized with 1N HCl and concentrated to remove dioxane.The reaction mixture was extracted with methylene chloride and theorganic layer was washed with brine. After drying (MgSO₄) andfilteration, the solvent was removed and the crude (17.7 g) waschromatographed (silica gel, hexane/ethyl acetate 1/1) to give pure VIA(28.2 g, 93%), DSC (mp) 101° C., Anal. calcd. for C₂₅ H₃₁ NO₈ : C,63.41, H, 6.60, N, 2.96. Found: C, 63.65, H, 6.68, N, 2.95.

EXAMPLE 9 Preparation of1,5-dideoxy-1,5-[{(phenylmethoxy)carbonyl}imino]-4,6-O-(R-phenylmethylene)-3-O-[{2-(trimethylsilyl)ethoxy}methyl]-D-glucitol(VIB)

The crude VB (60 g) as obtained above was dissolved in dioxane (500 ml)and tetrabutylammonium hydroxide (150 ml of 40% aqueous solution dilutedto 500 ml) was added. After stirring at room temperature for 72 hr, thereaction was neutralized with 1N HCl and concentrated to remove dioxane.The reaction mixture was extracted with methylene chloride (3×800 ml)and the organic layer was washed with brine. After drying (MgSO₄) andfilteration, the solvent was removed and the crude (90 g) waschromatographed (silica gel, hexane/ethyl acetate 8/2) to give pure VIB(28.2 g, 82% based on 2 steps from IV), DSC (mp) 108° C.; Anal. calcd.for C₂₇ H₃₇ NO₇ Si: C, 62.89, H, 7.23, N, 2.72. Found: C, 62.50, H,7.23, N, 2.65.

EXAMPLE 10 Preparation of1,5-dideoxy-1,5-[{(phenylmethoxy)carbonyl}imino]-4,6-O-(R-phenylmethylene)-3-O-[{2-{(1,1-dimethylethyl)dimethylsilyl}]-D-glucitol(VIC)

The crude VC (660 mg, 1.02 mmol) as obtained above was dissolved indioxane (20 ml) and tetrabutylammonium hydroxide (1.3 ml of 40% aqueoussolution diluted to 10 ml) was added. After stirring at room temperaturefor 16 hr, the reaction was neutralized with 1N HCl and concentrated toremove dioxane. The reaction mixture was extracted with methylenechloride and the organic layer was washed with brine. After drying(MgSO₄) and filteration, the solvent was removed and the crude (560 mg)was chromatographed (silica gel, hexane/ethyl acetate 8/2) to give VC(160 mg, 31%) and VIC (130 mg, 26%). ¹ H NMR (DMSO-D₆) 7.3-7.45 (complexband, 10H), 5.6 (s, 1H), 5.27 (d, J=5.2 Hz, 1H, exchanges with D₂ O),5.07 (S, 2H), 4.61 (dd, J=11 & 4.3 Hz, 1H), 4.2 (t, J=10.5 Hz, 1H), 3.82(dd, J=13.2 & 4 Hz, 1H), 3.64 (dd, J=10 & 8.5 Hz, 1H), 3.51 (dd, J=8.5 &6.2 Hz, 1H), 3.41 (complex band, 1H), 3.31 (ddd, J=10.2, 10.2 & 4.5 Hz,1H), 3.04 (dd, J=13.2 & 8.8 Hz, 1H), 0.78 (s, 9H), 0.00 (s, 6H).

EXAMPLE 11 Preparation of1,5-dideoxy-1,5-[{(phenylmethoxy)carbonyl}imino]-4,6-O-(R-phenylmethylene)-3-O-methyl-D-glucitol(VID)

To a solution of VD (360 mg, 0.72 mmol) in dioxane (10 ml),tetrabutylammonium hydroxide (1.4 ml of 40% aqueous solution diluted to7 ml) was added. After stirring at room temperature for 16 hr, thereaction was neutralized with 1N HCl and concentrated to remove dioxane.The reaction mixture was extracted with methylene chloride and theorganic layer was washed with aqueous sodium bicarbonate and brine.After drying (MgSO₄) and filtration, the solvent was removed and thecrude (270 mg) was chromatographed (silica gel, hexane/ethyl acetate1/1) to give VID (210 mg, 73%). ¹ H NMR (CDCl₃) 7.47 (m, 2H), 7.27-7.39(complex band, 8H), 5.54 (s, 1H), 5.12 (d, J=12 Hz, 1H), 5.07 (d, J=12Hz, 1H), 4.82 (dd, J=12 & 5 Hz, 1H), 4.39 (t, J=10 Hz, 1H), 4.22 (dd,J=13 & 5 Hz, 1H), 3.71 (t, J=10 Hz, 1H), 3.62 (s, 3H), 3.60 (complexband, 1H), 3.31 (ddd, J=10, 10 & 5 Hz, 1H), 3.23 (t, J=9 Hz, 1H), 2.94(broad s, 1H), 2.87 (dd, J=13 & 9 Hz, 1H).

EXAMPLE 12 Preparation of1,5-dideoxy-1,5-[{(phenylmethoxy)carbonyl}imino]-4,6-O-(R-phenylmethylene)-3-O-[{2-(methoxy)ethoxy}methyl]-L-sorbose(VIIA)

To a cold solution of dimethyl sulfoxide (2.55 ml, 35.5 mmol) inmethylene chloride (40 ml) at -70° C., trifluoroacetic anhydride (3.8ml, 26.62 mmol) in methylene chloride (40 ml) was added over 15-20 min.The reaction mixture was stirred for 10 min and then a solution of VIA(8.4 g, 17.74 mmol) in methylene chloride (200 ml) was added over 20min. The reaction temperature was allowed to rise to -20° C. over 90 minand then stirred at -30° C. for additional 2 hr. Reaction mixture wasrecooled (-70° C.) and triethylamine (8 ml) was added over 10 min. Afterstirring at -70° C. for 1 hr, the cold bath was removed and the reactionwas stirred for 2 hr. The reaction solution was diluted with methylenechloride and washed with water. After drying over MgSO₄, the organicfractions were filtered and concentrated. The crude liquid (9.45 g) waschromatographed (silica gel, hexane/ethyl acetate 1/1) to give VIIA (7.5g, 89%) as pure white solid, DSC (mp) 116° C.; Anal. calcd. for C₂₅ H₂₉NO₈.0.25 H₂ O: C, 63.08, H, 6.25, N, 2.94. Found: C, 63.03, H, 6.22, N,2.90.

EXAMPLE 13 Preparation of1,5-dideoxy-1,5-[{(phenylmethoxy)carbonyl}imino]-4,6-O-(R-phenylmethylene)-3-O-[{2-(trimethylsilyl)ethoxy}methyl]-L-sorbose(VIIB)

To a cold solution of dimethyl sulfoxide (6.58 ml, 0.092 mol) inmethylene chloride (30 ml) at -70° C., trifluoroacetic anhydride (10.1ml, 0.071 mol) in methylene chloride (30 ml) was added over 15-20 min.The reaction mixture was stirred for 20 min and then a solution of VIB(22.75 g, 0.046 mol) in methylene chloride (200 ml) was added over 45min. The reaction temperature was allowed to rise to -20° C. over 90 minand then stirred at -20° C. for an additional 4 hr. The reaction mixturewas recooled (-70° C.) and triethylamine (20 ml) was added over 10 min.After stirring at -70° C. for 45 min, the cold bath was removed and thereaction was stirred for 1 hr. The reaction solution was diluted withmethylene chloride and washed with water. After drying over MgSO₄, theorganic fractions were filtered and concentrated. The crude liquid (39g) was chromatographed (silica gel, hexane/ethyl acetate 75/25) to giveVIIB (22.1 g, 97%) as pure white solid, mp 112°-114° C.; Anal. calcd.for C₂₇ H₃₅ NO₇ Si.1H₂ O: C, 61.0, H, 7.01, N, 2.63. Found: C, 61.19, H,7.01, N, 2.72.

EXAMPLE 14 Preparation of1,5-dideoxy-1,5-[{(phenylmethoxy)carbonyl}imino]-4,6-O-(R-phenylmethylene)-3-O-[{2-[{(1,1-dimethylethylene)dimethylsilyl}]-L-sorbose(VIIC)

To a cold solution of dimethyl sulfoxide (0.37 ml, 5.21 mol) inmethylene chloride (5 ml) at -70° C., trifluoroacetic anhydride (0.57ml, 4.04 mmol) in methylene chloride (5 ml) was added over 10 min. Thereaction mixture was stirred for 10 min and then a solution of VIC (1.3g, 2.6 mmol) in methylene chloride (20 ml) was added over 15 min. Thereaction temperature was allowed to rise to -30° C. over 4 hr and thenstirred at -40° C. for additional 1 hr. Reaction mixture was recooled(-70° C.) and triethylamine (1 ml) was added over 10 min. After stirringat -70° C. for 1 hr, the cold bath was removed and the reaction wasstirred for 1 hr. The reaction solution was diluted with methylenechloride and washed with water. After drying over MgSO₄, the organicfractions were filtered and concentrated. The crude compound (1.48 g)was chromatographed (silica gel, hexane/ethyl acetate 8/2) to give VIIC(0.99 g, 76%). ¹ H NMR (CDCl₃) 7.47 (m, 2H), 7.32 (m, 8H), 5.56 (s, 1H),5.12 (d, J=12 Hz, 1H), 5.06 (d, J=12 Hz, 1H), 4.77 (dd, J=11, 5 Hz, 1H),4.25 (d, J=10 Hz, 1H), 4.18 (d, J=18 Hz, 1H), 4.14 (dd, J=11, 10 Hz,1H), 4.07 (d, J=18 Hz, 1H), 3.93 (t, J=10 Hz, 1H), 3.70 (td,=10, 5 Hz,1H), 0.86 (s, 9H), 0.11 (s, 3H), 0.0 (s, 3H).

EXAMPLE 5 Preparation of 1,5-dideoxy-1,5-[{(phenylmethoxy)carbonyl}imino]-4,6,-O-(R-phenylmethylene)-3-O-methyl-L-sorbose(VIID)

To a cold solution of dimethyl sulfoxide (75 μl, 1.06 mol) in methylenechloride (5 ml) at -70° C., trifluoroacetic anhydride (112 μl, 0.79mmol) in methylene chloride (5 ml) was added over 5 min. The reactionmixture was stirred for 10 min and then a solution of VID (210 mg, 0.53mmol) in methylene chloride (5 ml) was added over 10 min. The reactiontemperature was allowed to rise to -30° C. over 3 hr and then stirred at-30° C. for an additional 4 hr. Reaction mixture was recooled (-70° C.)and triethylamine (0.4 ml) was added over 10 min. After stirring at -70°C. for 1 hr, the cold bath was removed and the reaction was stirred for1 hr, the cold bath was removed and the reaction was stirred for I hr.The reaction solution was diluted with methylene chloride and washedwith water. After drying over MgSO₄, the organic fractions were filteredand concentrated. The crude compound (260 mg) was chromatographed(silica gel, hexane/ethyl acetate 6/4) to give VIID (190 mg, 91%). ¹ HNMR (CDCl₃) 7.51 (m, 2H), 7.36 (m, 8H), 5.61 (s, 1H), 5.17 (d, J=12 Hz,1H), 5.10 (d, J=12 Hz, 1H), 4.82 (dd, J=11, 5 Hz, 1H), 4.25 (d, J=16 Hz,1H), 4.21 (dd, J=11, 10 Hz, 1H), 4.11 (d, J=16 Hz, 1H), 4.06 (t, J=10Hz, 1H), 3.96 (d, J=10 Hz, 1H), 3.77 (td,=10, 5 Hz, 1H), 3.64 (S, 3H).

EXAMPLE 16 Preparation of1,5-dideoxy-2-C-methyl-1,5-[{(phenylmethoxy)carbonyl}imino]-4,6-O-(R-phenylmethylene)-3-O-[{2-[{(1,1-dimethylethyl)dimethylsilyl}]-D-mannitol(VIIIB)

To a cold solution of VIIC (620 mg, 1.25 mmol) in tetrahydrofuran (15ml) at -70° C., methyl magnesium bromide (1.25 ml, 3M in Et₂ O, 3.75mmol) was added over 10 min. The reaction mixture was allowed to warm to-30° C. over 3 hr. After stirring at -20° to -30° C. for 2 hr, thereaction was quenched by adding saturated aqueous ammonium chloride andextracted with ethyl acetate. The organic layer was washed with brineand dried (MgSO₄), filtered and concentrated. The crude product (600 mg)was chromatographed (silica gel, hexane/ethyl acetate 8/2) to give pureVIIIB (440 mg, 67%). ¹ H NMR (CDCl₃) 7.49 (m, 2H), 7.39 (m, 8H), 5.54(s,1H), 5.17 (d, J=12 Hz, 1H), 5.13 (d, J=12 Hz, 1H), 4.72 (dd, J=12, 5Hz, 1H), 4.66 (dd, J=12, 10 Hz, 1H), 4.28 (d, J=14 Hz, 1H), 3.9 (dd,J=10, 8 Hz, 1H), 3.55 (d, J=8 Hz, 1H), 3.25 (td, J=10, 5 Hz, 1H), 2.83(dd, J=14, 2 Hz, 1H), 2.73 (d, J=2 Hz, 1H), 1.24 (s, 3H), 0.87 (s, 9H),0.05 (s, 3H), -0.05 (s, 3H).

EXAMPLE 17 Synthesis of phenylmethyl8β-[{(1,1-dimethylethyl)dimethylsilyl}oxy]hexahydro-7-hydroxy-2R,2.alpha.-phenyl-7-[(trimethylsilyl)methyl]-5H-4aα,8aβ-1,3-dioxino[5,4-b ]pyridine-5-carboxylate (IXB)

The cerium chloride (1.5 g, 6 mmol) was dried under vacuum (0.1 mm Hg)with stirring at 140° C. for 18 hr. After cooling to approx 20° C. drytetrahydrofuran (50 ml) was added and the mixture was stirred underargon for 2 hr. The reaction mixture was cooled to -78° C. andtrimethylsilylmethyllithium (12 ml, 1M solution in pentane, 12 mmol) wasadded to the reaction flask over 10 min. After stirring for i hr, asolution of VIIC (1.35 g, 2.7 mmol) in THF (35 ml) was added over 20min. The bath temperature was allowed to rise to -10° C. over 4 hrs andstirred at -10° C. for 18 hrs. The reaction mixture was quenched withethylenediamine (1.5 ml), stirred for 40 min and then diluted with ethylacetate. The organic layer was separated and washed with aqueouspotassium carbonate and brine. After drying the organic layer overMgSO₄, the solvent was removed and the crude product (1.82 g)chromatographed (silica gel, hexane/ethyl acetate 8/2) to give IXB (680mg, 43%). ¹ H NMR (CDCl₃) 7.25-7.57 (complex band, 10H), 5.52 (s, 1H),5.14 (d, J=12 Hz, 1H), 5.10 (d, J=12 Hz, 1H), 4.69 (m, 2H), 4.42 (d,J=14 Hz, 1H), 3.85 (dd, J=10, 8 Hz, 1H), 3.48 (d, J=8 Hz, 1H), 3.24(distorted q, J=9 Hz, 1H), 2.73 (broad d, J=14 Hz, 1H), 2.65 (broad s,1H), 1.4 (d, J=15 Hz, 1H), 0.86 (s, 9H), 0.62 (d, J=15 Hz, 1H), 0.06 (s,9H), 0.04 (s, 3H), -0.07 (s, 3H).

EXAMPLE 18 Preparation of1,5-dideoxy-2-C-methyl-1,5-]{(phenylmethoxy)carbonyl}imino]-4,6-O-(R-phenylmethylene)-3-O-[{2-(methoxy)ethoxy}methyl]-D-glucitol(XA) and1,5-dideoxy-2-C-methyl-1,5-[{(phenylmethoxy)carbonyl}imino]-4,6-O-(R-phenylmethylene)-3-O-[{2-(methoxy)ethoxy}methyl}-Dmannitol XB

To a cold solution of VIIA (4.92 g, 10.43 mmol) in tetrahydrofuran (120ml) at -70° C., methyl magnesium bromide (10.5 ml, 3M in Et₂ O, 31.3mmol) was added over 10 min. The reaction mixture was stirred at -70° C.for 2 hr and then allowed to warm to -30° C. over 2 hr. After stirringat -30° C. for 4 hr, the reaction was quenched by adding saturatedaqueous ammonium chloride (700 ml) and extracted with ethyl acetate. Theorganic layer was washed with brine and dried (MgSO₄), filtered andconcentrated. The crude (5.4 g) was chromatographed (silica gel,hexane/ethyl acetate 1/1) to give XA (1.08 g, 21%) and XB (2.2 g,43.3%). XA: mp 75°-76° C.; Anal calcd. for C₂₆ H₃₃ NO₈ : C,64.05, H,6.82, N, 2.87 Found C, 63.74, H, 6.92, N, 2.80; ¹ H NMR (CDCl₃) 7.48 (m,2H), 7.37 (m, ell), 5.53 (s,1H), 5.11 (d, J=12 Hz, 1H), 5.06 (d, J=12Hz, 1H), 4.87 (d, J =5 Hz, 1H), 4.85 (d, J=5Hz, 1H), 4.83 (dd, J=12, 5Hz, 1H), 4.52 (dd, J=12, 11 Hz, 1H), 4.35 (broad s, 1H), 4.18 (d, J=14Hz, 1H), 3.90 (m, 1H), 3.68 (m, 1H), 3.63 (dd, J=9.5, 9 Hz, 1H), 3.56(d, J=9 Hz, 1H), 3.53 (m, 2H), 3.37 (s, 3H), 3.26 (ddd, J=11, 9.5, 5 Hz,1H), 2.79 (d, J=14 Hz, 1H), 1.23 (s, 3H). XB: Anal calcd. for C₂₆ H₃₃NO₈ 0.8H₂ O: C,62.21, H, 6.95, N, 2.79 Found C, 62.31, H, 6.71, N, 2.74;¹ H NMR (CDCl₃) 7.48 (m, 2H), 7.37 (m, 8H), 5.54 (s,1H), 5.13 (d, J=12Hz, 1H), 5.09 (d, J=12 Hz, 1H), 5.06 (d, J=7 Hz, 1H), 4.83 (d, J=7Hz,1H), 4.74 (dd, J=12, 5 Hz, 1H), 4.60 (dd, J=12, 10 Hz, 1H), 4.21 (d,J=14 Hz, 1H), 4.08 (dd, J=10, 9 Hz, 1H), 3.76 (m, 1H), 3.68 (m, 1H),3.55 (d, J=9 Hz, 1H), 3.36 (m, 2H), 3.31 (s, 3H), 3.23 (ddd, J=11, 10, 5Hz, 1H), 2.8 (d, J=14 Hz, 1H), 2.49 (broad s, 1H), 1.27 (s, 3H).

EXAMPLE 19 Preparation of 1,5-dideoxy-2-C-methyl-1,5-]{(phenylmethoxy)carbonyl}imino]-4,6-O-(R-phenylmethylene-3-O-[{2-(trimethylsilyl)ethoxy}methyl]-D-glucitol(XIA) and1,5-dideoxy-2-C-methyl-1,5-[{(phenylmethoxy)carbonyl}imino]-4,6-O-(R-phenylmethylene)-3-O-[{2-(trimethylsilyl)ethoxy}methyl]-D-mannitol (XIB)

To a cold solution of VIIB (720 mg, 1.47 mmol) in tetrahydrofuran (25 ml) at -70° C. methyl magnesium bromide (15 ml 3M in Et₂ O, 4.41 mmol) wasadded over 10 min. The reaction mixture was allowed to warm to -30° C.over 3 hr. After stirring at -20° to -30° C. for 4 hr, the reaction wasquenched by adding saturated aqueous ammonium chloride and extractedwith ethyl acetate (2×150 ml). The organic layer was washed with brineand dried (MgSO₄), filtered and concentrated. The crude (920 mg ) waschromatographed (silica gel, hexane/ethyl acetate 75/25) to give pureXIA (530 mg, 68%) and XIB (42 mg, 5%). X1A: Anal calcd. for C₂₈ H₃₉ NO₇Si.0.5H₂ O: C, 62.43, H, 7.48, N, 2.6 Found C, 62.34, H, 7.34, N, 2.56;¹ H NMR (CDCl₃) 7.48 (m, 2H), 7.37 (m, 8H), 5.54 (s,1H), 5.10 (d, J=12Hz, 1H), 5.05 (d, J=12 Hz, 1H), 4.88 (d, J =7 Hz, 1H), 4.82 (dd, J=11.5,4 Hz, 1H), 4.68 (d, J=7Hz, 1H), 4.52 (br.t, J=11.5, 11 Hz, 1H), 4.43 (s,1H), 4.19 (d, J=14 Hz, 1H), 3.86 (m, 1H), 3.63 (dd, J =10, 9 Hz, 1H),3.56 (m, 1H), 3.44 (d, J=9 Hz, 1H), 3.25 (td, J=10, 4 Hz, 1H), 2.77 (d,J=14 Hz, 1H), 1.21 (s, 3H). 0.94 (m, 2H), 0 (s, 9H). X1B: ¹ H NMR(CDCl₃) 7.48 (m, 2H), 7.37 (m, 8H), 5.57 (s,1H), 5.16 (d, J=12 Hz, 1H),5.11 (d, J=12 Hz, 1H), 5.02 (d, J=7 Hz, 1H), 4.83 (d, J=7Hz, 1H), 4.74(dd, J=11.5, 4.7 Hz, 1H), 4.62 (br.t, J=11.5, 10.2 Hz, 1H), 4.24 (d,J=14 Hz, 1H), 4.10 (dd, J=9.9, 8.8 Hz, 1H), 3.76 (m, 1H), 3.56 (m, 1H),3.54 (m, 1H), 3.25 (td, J=10, 4.7 Hz, 1H), 2.83 (dd, J=14, 1.9 Hz, 1H),2.37 (d, J=1.9 Hz, 1H), 1.3 (s, 3H). 0.91 (m, 2H), 0 (s, 9H).

EXAMPLE 20 Preparation of1,5-dideoxy-2-C-methyl-1,5-[{(phenylmethoxy)carbonyl}imino]-4,6-O-(R-phenylmethylene)-3-O-methyl-D-glucitol(XIIA) and1,5-dideoxy-2-C-methyl-1,5-[{(phenylmethoxy)carbonyl}imino]-4,6-O-(R-phenylmethylene)-3-O-methyl-D-mannitol(XIIB)

To a cold solution of VIID (193 mg, 0.5 mmol) in tetrahydrofuran (10 ml) at -70° C., methyl magnesium bromide (0.5 ml, 3M in Et₂ O, 1.5 mmol)was added over 10 min. The reaction mixture was allowed to warm to -30°C. over 2 hr. After stirring at -20° to -30° C. for 4 hr, the reactionwas quenched by adding saturated aqueous ammonium chloride and extractedwith ethyl acetate (50 ml). The organic layer was washed with brine anddried (MgSO₄), filtered and concentrated. The crude (190 mg) waschromatographed (silica gel, hexane/ethyl acetate 1/1) to give pure XIIA(111 mg, 54%) and XIIB (7.1 mg, 4%). XIIA. Anal calcd. for C₂₃ H₂₇NO₆.0.2H₂ O: C, 66.24, H, 6.62, N, 3.32 Found C, 66.12, H, 7.17, N,3.05; ¹ H NMR (CDCl₃) 7.49 (m, 2H), 7.36 (m, 8H), 5.57 (s,1H), 5.12 (d,J=12 Hz, 1H), 5.07 (d, J=12 Hz, 1H), 4.84 (dd, J =12, 5 Hz, 1H), 4.50(dd, J=12, 10 Hz, 1H), 4.10 (d, J=13 Hz, 1H), 3.69 (t, J=10 Hz, 1H),3.66 (s, 3H), 3.31 (td, J=10, 5 Hz, 1H), 3.26 (d, J=10 Hz, 1H), 2.84 (d,J=13 Hz, 1H), 2.25 (s, 1H), 1.22 (s, 3H). XIIB. Anal calcd. for C₂₃ H₂₇NO₆.O: C,66.81, H, 6.58, N, 3.39 Found C, 66.91, H, 6.90, N, 2.94; ¹ HNMR (CDCl₃) 7.25-7.5 (m, 10H), 5.60 (s,1H), 5.14 (d, J=12 Hz, 1H), 5.09(d, J=12 Hz, 1H), 4.73 (dd, J=11, 5 Hz, 1H), 4.62 (dd, J=11, 10.6 Hz,1H), 4.22 (d, J=14 Hz, 1H), 4.06 (dd, J=10, 8.7 Hz, 1H), 3.66 (s, 3H),3.21 (td, J =10, 4.6 Hz, 1H), 3.08 (d, J=8.7 Hz, 1H), 2.79 (dd, J=14,1.8 Hz, 1H), 2.36 (d, J=1.8 Hz, 1H), 1.26 (s, 3H).

EXAMPLE 21 Preparation of1,5-dideoxy-2-C-methyl-1,5-[{(phenylmethoxy)carbonyl}imino]-4,6-O-(R-phenylmethylene)-D-glucitol(XIII)

To a homogenous solution of XIA (7.8 g, 14.75 mmol) in tetrahydofuran(150 ml), tetrabutylammonium fluoride (88 ml, 1M solution intetrahydofuran, 88 mmol) was added. After stirring at room temperaturefor 25 min, the solvent was removed and the residue dried under vacuumfor 4 hr. The dried product was suspended in1,3-dimethyl-3,4,5,6-tetrahydro-2(1H)-pyrimidinone (DMPU) (50 ml) andmolecular sieves (4A°, pre-dried, 5 g) were added. The reaction mixturewas heated at 80° C. for 18 hr, cooled to room temperature and dilutedwith Et₂ O (1000 ml). The ethereal layer was separated, washed withwater, dried (MgSO₄) and concentrated. The crude product (13.6 g) waschromatographed (silica gel, hexane/ethyl acetate 1/1) to give XIII(3.83 g, 65%) as pure white solid, mp 104°-6° C.; Anal. calcd. for C₂₂H₂₅ NO₆ 0.3H₂ O: C, 65.27, H, 6.37, N, 3.46. Found: C, 65.22, H, 6.29,N, 3.42. ¹ H NMR (CDCl₃) 7.48 (m, 2H), 7.37 (m, 8H), 5.51 (s,1H), 5.11(d, J=12 Hz, 1H), 5.06 (d, J=12 Hz, 1H), 4.81 (dd, J=12, 5 Hz, 1H), 4.44(dd, J=12, 10 Hz, 1H), 4.06 (d, J=14 Hz, 1H), 3.59 (d, J=9 Hz, 1H), 3.51(dd, J=10, 9 Hz, 1H), 3.23 (td, J=10, 5 Hz, 1 H), 2.73 (d, J=14 Hz, 1H),2.98 (broad s, 1H), 2.58 (broad s, 1H), 1.2 (s, 3H).

EXAMPLE 22 Preparation of1,5-dideoxy-1,5-imino-2-C-methyl-4,6-O-(R-phenylmethylene)-D-glucitol(XIV)

To a solution of XIII (3 g, 7.5 mmol) in methanol (200 ml) in aFischer-Porter bottle, 10% Pd on C (375 mg) was added. The bottle wassealed, purged with nitrogen, purged with hydrogen and then pressurizedto 60 psi hydrogen pressure. After agitating at room temperature for 70min, the reaction was vented to remove hydrogen. The catalyst wasfiltered and the residue washed with more methanol. The combined organicfilterates were concentrated and the crude product was chromatographed(silica gel, methylene chloride / methanol/30% aqueous ammoniumhydroxide 90/10/1) to give pure XIV (1.68 g, 84%) as white solid. Anal.calcd. for C₁₄ H₁₉ NO₄ 0.25 H₂ O: C, 62.32, H, 7.28, N, 5.19. Found: C,62.28, H, 7.44, N, 5.06.

EXAMPLE 23 Synthesis of 1,5-imino-1,5-dideoxy-2-C-methyl-D-glucitol XVMethod A (Using Transfer Hydrogenation)

To a clear solution of XIV (550 mg, 2.07 mmol) in ethanol (20 ml) andcyclohexene (40 ml), 20% Pd(OH)₂ on C (500 mg) was added. Afterrefluxing the mixture for 6 hr, more catalyst (300 mg) and cyclohexene(80 ml) were added. The mixture was refluxed for 18 hr and additionalamounts of catalyst (200 mg) and cyclohexene (80 ml) were added. Afterrefluxing for an additional 24 hrs, the reaction mixture was cooled andfiltered. The residue was washed with methanol (300 ml) and thefilterate was concentrated to give the residue (620 mg). The residue wassubjected to chromatography (silica gel, methylene chloride/methanol/30%ammonium hydroxide 90/10/1 and then methylene chloride/methanol/30%ammonium hydroxide 50/50/2.5) and gave recovered starting material XIV(90 mg, 16%) and XV (285 mg, 73%) as pure white solid. DSC (mp) 214°-16°C. Anal. calcd. for C₇ H₁₅ NO.sub. 4 0.1 H₂ O: C, 46.97, H, 8.56, N,7.82. Found: C, 46.87, H, 8.62, N, 7.79.

Method B (Using Sodium/liq. Ammonia)

The compound XIV (180 mg, 0.68 mmol) was dissolved in liquid ammonia (20ml)at -70° C. and was reduced by adding small pieces of sodium metal.The reaction mixture was stirred for 20 mins at -60° C. The cold bathwas removed and the excess ammonia was allowed to escape. The whiteresidue was quenched with water and the solution was passed thru anion-exchange column (Amberlite IRA 400, OH). The basic fractions werecollected and concentrated. The crude product (190 mg) was purified bychromatographed as in Method A to give XV (55 mg, 45%) identical to theproduct of Method A.

EXAMPLE 24 Synthesis of 1,5-Butylimino-1,5-dideoxy-2-C-methyl-D-glucitol(XVIA)

To a solution of XV (170 mg, 0.96 mmol) and butyraldehyde (150 mg, 2.1mmol) in methanol (12 ml), water (3ml) and tetrahydrofuran (6 ml) in aFischer-Porter bottle, 5% Pd on C (35 mg) was added. The bottle wassealed, purged with nitrogen, purged with hydrogen and then pressurizedto 5 psi hydrogen pressure. After agitating at room temperature for 70hr, the reaction was vented to remove hydrogen. The catalyst wasfiltered and the residue washed with more methanol. The combined organicfilterates were concentrated and the crude product (260 mg) waschromatographed (silica gel, methylene chloride/methanol/30% ammoniumhydroxide 85/15/1.5) to give XVIA (188 mg, 84%). mp 68°-70° C., Anal.calcd. for C₁₁ H₂₃ NO₄ 0.25 H₂ O: C, 55.56, H, 9.96, N, 5.89. Found: C,55.58, H, 9.86, N, 5.79.

EXAMPLE 25 Synthesis of 1,5-(3-phenylpropylimino)-1,5-dideoxy-2-C-methyl-D-glucitol (XVIB)

The type reaction of Example 24 was repeated using XV (130 mg, 0.73mmol) and 3-phenylpropionaldehyde (130 mg, 0.97 mmol), 5% Pd on C (30mg) in methanol (12 ml), water (3 ml) and tetrahydrofuran (3 ml). Thecrude (220 mg) obtained after work up was purified on column (silicagel, methylene chloride/methanol/30% ammonium hydroxide 75/25/1) to givepure XVIB (140 mg, 65%), DSC (mp) 94° C., Anal calcd for C₁₆ H₂₅ NO₄0.4H₂ O: C, 63.51, H, 8.59, N, 4.63. Found: C, 63.56, H, 8.36, N, 4.66.

EXAMPLE 26 Synthesis of1,5-(2-ethylbutylimino)-1,5-dideoxy-2-C-methyl-D-glucitol (XVIC)

The type reaction of Example 24 was repeated using XV (130 mg, 0.73mmol) and 2-ethylbutyraldehyde (130 mg, 1.3 mmol), 5% Pd on C (30 mg) inmethanol (12 ml), water (3 ml) and tetrahydrofuran (3 ml). The crudeproduct (220 mg) obtained after work up was chromatographically purifiedon a column (silica gel, methylene chloride/methanol/30% ammoniumhydroxide 75/25/1) to give pure XVIC (70 mg, 37%), mp 78°-80° C. Analcalcd for C₁₃ H₂₇ NO₄ 0.3H₂ O: C, 58.53, H, 10.43, N, 5.25 Found: C,58.64, H, 10.15, N, 5.35.

EXAMPLE 27 Synthesis of1,5-dideoxy-2-C-methyl-1,5-[(1-oxabutyl)imino]-D-glucitol, 6-butanoate(XVIIA)

A solution of XV (35 mg, 0.2 mmol) in butyric anhydride (3 ml) wasstirred at room temperature. After 28 hr, the solvent was removed underargon at room temperature and the crude liquid was passed through ashort column (silica gel, methylene chloride/methanol/ammonium hydroxide90/10/1) to give XVIIA (29 mg, 46%), ¹ H NMR (CD₃ OD) 5.08 (broad dd,J=10, 4 Hz, 1H), 4.81 (dd, J=12, 10 Hz, 1H), 4.64 (dd, J=12, 10 Hz, 1H),4.36 (broad D, J=10 Hz, 1H), 4.29 (d, J=14 Hz, 1H), 4.12 (dd, J=12, 4Hz, 1H), 4.06 (dd, J=12, 4 Hz, 1H), 3.82 (dd, J=4, 2 Hz, 2H), 3.47 (s,2H), 3.46 (d, J=4 Hz, 1H), 3.45 (d, J=4 Hz, 1H), 2.94 (d, J=14 Hz, 1H),2.56 (ddd, J=15, 8, 6 Hz, 1H), 2.43 (t, J=7 Hz, 1H), 2.36 (ddd, J=15, 8,7 Hz, 1H), 2.28 (t, J=7 Hz, 2H), 2.24 (t, J=7 Hz, 2H), 1.53-1.75(complex band, 8H), 1.20 (s, 6H), 0.97 (t, J=7 Hz, 3H), 0.92 (t, J=7 Hz,3H). It might be noted that the integrals to NMR signals are assignedassuming that 1H=one proton signal of one rotamer.

EXAMPLE 28 Synthesis of1,5-dideoxy-2-C-methyl-1,5-[(1-oxabutyl)imino]-D-glucitol (XVIIB)

To a solution of XV (22 mg, 0.12 mmol) in methanol (0.5 ml), butyricanhydride (0.5 ml) was added and the reaction mixture was stirred atroom temperature. After 3 hr, the solvent was removed under argon atroom temperature and the crude liquid was passed through a short column(silica gel, methylene chloride/methanol/ammonium hydroxide 90/10/1) togive XVIIA (6.9 mg, 10%) and XVIIB (27 mg, 88%). ¹ H NMR (CD₃ OD) 4.32(d, J=14 Hz, 1H), 4.17 (broad dd, J=7, 1.5 Hz, 1H), 4.02 (dd, J=12, 9.5Hz, 1H), 3.89 (broad t, J=2.4 Hz, 1H), 3.81 (dd, J=12, 7.4 Hz, 1H), 3.79(m, 1H), 3.78 (m, 1H), 3.76 (dd, J=12, 6.1 Hz, 1H), 3.63 (dd, J=12, 4.3Hz, 1H), 3.51 (d, J=14 Hz, 1H), 3.45 (m, 2H), 3.40 (d, J=14 Hz, 1H),2.92 (d, J=14 Hz, 1H), 2.58 (m, 1H), 2.46 (m, 1H), 2.46 (t, J=7.3 Hz,2H), 1.67 (m, 4H), 1.18 (s, 6H), 0.97 (t, J=7 Hz, 3H), 0.96 (t, J=7 Hz,3H). It might be noted that the integrals to NMR signals are assignedassuming that 1H=one proton signal of one rotamer. MS (EI) 247 (M+)

EXAMPLE 29 Synthesis of1,5-(butylimino)-1,5-dideoxy-2-C-methyl-D-glucitol, (3 and/or 4),6-perbutanoate (XVIIIA, XVIIIB & XBIIIC)

To a suspension of XVIA (35 mg, 0.15 mmol) in pyridine (3 ml), butyricanhydride (145 μl, 0.89 mmol) was added and the mixture was stirred for7 days. The solvent was removed under argon at room temperature and thecrude (62 mg) was chromatographed (silica gel, hexane/ethyl acetate 1/1)to give XVIIIA (6 mg, 9%), XVIIIB (16 mg, 29%) & XVIIIC (9 mg, 16%).XVlIIA ¹ H NMR (CDCl₃) 4.99 (t, J=6 Hz, 1H), 4.80 (d, J=6.4 Hz, 1H),4.25 (dd, J =12, 5 Hz, 1H), 4.21 (d, J=12, 5 Hz, 1H), 3.07 (broad s,1H), 2.83 (d, J=12 Hz, 1H), 2.82 (m, 1H), 2.64 (m, 1H), 2.54 (m, 1H),2.2-2.39 (complex band, 7H), 1.53-1.7 (complex band, 6H), 1.43 (m, 2H),1.3 (m, 2H), 1.22 (s, 3H), 0.88-0.97 (complex band, 12H); MS (Cl, NH₃)444 (M+1).

XVIIIB ¹ H NMR (CDCl₃) 4.69 (d, J=7.7 Hz, 1H), 4.43 (dd, J=12.2, 3.8 Hz,1H), 4.35 (dd, J=12.2, 3.8 Hz, 1H), 3.56 (broad t, J=7.4 Hz, 1H), 2.78(d, J=11.7 Hz, 1H), 2.71 (m, 1H), 2.58 (td, J=7.4, 3.8 Hz, 1H), 2.49 (m,1H), 2.28-2.4 (complex band, 4H), 1.61-1.73 (complex band, 4H), 1.43 (m,2H), 1.3 (m, 2H), 1.22 (s, 3H), 0.88-1 (complex band 9H); MS (Cl, NH₃)374 (M+1) XVIIIC ¹ H NMR (CDCl₃) 4.84 (t, J=7 Hz, 1H), 4.34 (dd, J=12.2,4 Hz, 1H), 4.20 (dd, J=12.2, 3.9 Hz, 1H), 3.48 (dd, J=7.2, 5.3 Hz, 1H),2.80 (d, J=11.5 Hz, 1H), 2.71 (m, 1H), 2.68 (m, 1H), 2.53 (m, 1H),2.25-2.38 (complex band 4H), 1.62-1.71 (complex band, 4H), 1.42 (m, 2H),1.32 (m, 2H), 1.28 (s, 3H), 0.88-1 (complex band, 9H); MS (Cl, NH₃) 374(M+1).

EXAMPLE 30 Synthesis of phenylmethylhexahydro-8β-hydroxy-7-hydroxy-2R,2α-phenyl-7-[(trimethylsilyl)methyl]-5H-4aα,8aβ-1,3-dioxino[5,4-b]pyridine-5-carboxylate (XIX)

To a solution of IXB (60 mg, 0.1 mmol) in THF (4 ml), tetrabutylammoniumfluoride (0.3 ml, 1M solution in THF, 0.3 mmol) was added and thecontents were stirred at 20° C. for 18 hr. The reaction mixture wasdiluted with ethyl acetate and the organic layer was washed with waterand brine. After drying (MgSO₄), the solvent was removed and the crudeproduct (58 mg) was chromatographed (silica gel, hexane/ethyl acetate7/3) to give XIX (40 mg, 85%). ¹ H NMR (CDCl₃) 7.49 (m, 2H), 7.37 (m,8H), 5.57 (s, 1H), 5.14 (d, J=12 Hz, 1H), 5.10 (d, J=12 Hz, 1H), 4.76(dd, J=12, 5 Hz, 1H), 4.61 (dd, J=12, 10 Hz, 1H), 4.38 (d, J=14 Hz, 1H),3.90 (dd, J=10, 8 Hz, 1H), 3.46 (dd, J=8, 2.5 Hz, 1H), 3.22 (td, J=10, 5Hz, 1H), 2.74 (dd, J=14, 2 Hz, 1H), 2.63 (d, J=2.5 Hz, 1H), 2.29 (d, J=2Hz, 1H), 1.33 (d, J=15 Hz, 1H), 0.80 (d, J=15 Hz, 1 H), 0.07 (s, 9H).

EXAMPLE 31 Synthesis ofphenylmethyl-hexahydro-8β-hydroxy-7-methylene-2R, 2α-phenyl-5H-4aα,8aβ-1,3-dioxino[5,4-b]pyridine-5-carboxylate (XXA)

To a solution of XIX (40mg, 0.084 mmol) in acetonitrile (2 ml),tetrabutylammonium fluoride (0.5 ml, 1M solution in THF, 0.5 mmol) wasadded and the contents were refluxed for 18 hr. After cooling to roomtemperature, the reaction mixture was diluted with ethyl acetate and theorganic layer was washed with water and brine. After drying (MgSO₄), thesolvent was removed and the crude product (32 mg) was chromatographed(silica gel, hexane/ethyl acetate 7/3) to give XXA (21 mg, 65%). ¹ H NMR(CDCl₃) 7.51 (m, 2H), 7.37 (complex band, 8H), 5.58 (s, 1H ), 5.35(broad s, 1H ), 5.13 (broad s, 1H ), 5.12 (s, 2H), 4.81 (dd, J=12, 5 Hz,1H), 4.61 (d, J=15 Hz, 1H), 4.44 (dd, J=12, 10 Hz, 1H), 4.27 (broad d, J=9 Hz, 1H), 3.63 (dd, J=10, 9 Hz, 1H), 3.55 (d, J=15 Hz, 1H), 3.42 (td,J=10, 5 Hz, 1H), 2.68 (broad s,1H).

EXAMPLE 32 Synthesis ofphenylmethyl-hexahydro-8β-hydroxy-7-methylene-2R, 2α-phenyl-5H-4aα,8aβ-1,3-dioxino [5,4-b]pyridine-5-carboxylate (XXA)

To a solution of IXB (600mg, 1.03 mmol) in acetonitrile (5 ml),tetrabutylammonium fluoride (7 ml, 1M solution in THF, 7 mmol) was addedand the contents were refluxed for 18 hr. After cooling to roomtemperature, the reaction mixture was diluted with ethyl acetate and theorganic layer was washed with water and brine. After drying (MgSO₄), thesolvent was removed and the crude product (480 mg) was chromatographed(silica gel, hexane/ethyl acetate 7/3) to give XXA (112 mg, 29%)identical to the product of Example 31.

EXAMPLE 33 Synthesis of phenylmethyl8β-[{(1,1-dimethylethyl)dimethylsilyl}oxy]hexahydro-7-methylene-2R,2α-phenyl-5H-4aα, 8aβ-1,3-dioxino[5,4-b]pyridine-5-carboxylate (XXB)

To a homogenous solution of XXA (100mg, 0.26 mmol) in methylene chloride(5 ml), N,N-diisopropylethylamine (99%, 140 μl, 0.78 mmol) andtert-butyldimethylsilyl trifluoromethanesulfonate (120 μl, 0.52 mmol)were added. After stirring at room temperature for 2 hr, the reactionmixture was diluted with methylene chloride (700 ml) and washed withaqueous sodium bicarbonate, water and brine. After drying (MgSO₄) andfilteration, the organic solvent was removed to give XXB (123 mg, 95%)and was used in the next step without further purification. ¹ H NMR(CDCl₃) 7.48 (m, 2H), 7.34 (m, 8H), 5.52 (s, 1H), 5.31 (t, J=1.5 Hz,1H), 5.10 (d, J=12 Hz, 1H), 5.07 (d, J=12 Hz, 1H), 5.06 (broad s, 1H),4.72 (dd, J=12, 5 Hz, 1H), 4.62 (d, J=14 Hz, 1H), 4.50 (dd, J=12, 10 Hz,1H), 4.22 (dt, J=8, 1.5 Hz, 1H), 3.58 (dd, J=10, 8 Hz, 1H), 3.43 (broadd, J=14 Hz, 1H), 3.37 (td, J=10, 5 Hz, 1H), 0.86 (s, 9H), 0.03 (s, 3H),-0.03 (s, 3H).

EXAMPLE 34 Synthesis of phenylmethyl8β-[{(1,1-dimethylethyl)dimethylsilyl}oxy]tetrahydro-2R,2α-phenylspiro-[5H-4aα, 8aβ-1,3-dioxino[5,4-b]pyridine-7-(6H),2'-oxirane]5-carboxylate (XXI & XXII)

To a methylene chloride (5 ml) solution of XXB (120 mg, 0.24 mmol),3-chloroperbenzoic acid (68 mg, 0.31 mmol) was added. The mixture wasstirred at 20° C. for 20 hr and more 3-chloroperbenzoic acid (75 mg,0.34 mmol) was added. After 18 hr, the reaction mixture was diluted withmethylene chloride and washed with aqueous sodium bicarbonate, water andbrine. After drying (MgSO₄), the solvent was removed and the crudeproduct (120 mg) was chromatographed (silica gel, hexane/ethyl acetate75/25) to give mixture of epoxides XXI (22 mg, 18%) and XXII (70 mg,57%). XXI ¹ H NMR (CDCl₃) 7.49 (m, 2H), 7.36 (m, 8H), 5.55 (s, 1H), 5.14(d, J=12 Hz, 1H), 5.07 (d, J=12 Hz, 1H), 4.79 (dd, J=12, 5 Hz, 1 H),4.49 (dd, J=12, 10 Hz, 1H), 3.97 (d, J=8 Hz, 1H), 3.85 (d, J=14 Hz, 1H),3.71 (dd, J=10, S Hz, 1H), 3.39 (td, J=10, 5 Hz, 1H), 3.28 (dd, J=14, 1Hz, 1H), 3.07 (dd, J=6, 1 Hz, 1H), 2.60 (d, J=6 Hz, 1H), 1.60 (broad s,1H), 0.82 (s, 9H), 0.03 (s, 3H), -0.04 (s, 3H). XXII ¹ H NMR (CDCl₃)7.49 (m, 2H), 7.36 (m, 8H), 5.56 (s, 1H), 5.11 (s, 2H), 4.87 (dd, J=12,5 Hz, 1H), 4.55 (dd, J=12, 10 Hz, 1H), 4.07 (d, J= 9 Hz, 1H), 3.93 (d,J=15 Hz, 1H), 3.91 (dd, J=10, 9 Hz, 1H), 3.40 (td, J=10, 5 Hz, 1H), 3.37(d, J=15 Hz, 1H), 3.11 (d, J=5 Hz, 1H), 2.70 (d, J=5 Hz, 1H), 0.82 (s,9H), 0.01 (s, 3H), -0.07 (s, 3H).

EXAMPLE 35 Synthesis of1,5-dideoxy-3-O-[(1,1-dimethylethyl)dimethylsilyl]-2-C-methyl-1,5-imino-4,6-O-(R-phenylmethylene)-D-glucitol(XXIII)

To a solution of XXI (22 mg, 0.04 mmol) in tetrahydrofuran (3 ml),lithium aluminum hydride (20 mg, 0.5 mmol) was added. After refluxingfor 2 hr, the reaction mixture was cooled to room temperature anddiluted with ethyl acetate. After stirring for 15 min., the reaction wascarefully quenched by adding drops of 1N HCl and diluted with water. Themixture was extracted with ethyl acetate and the organic layer waswashed with water and brine. After drying (MgSO₄), the solvent wasremoved and the crude product (23 mg) was chromatographed (silica gel,hexane/ethyl acetate 1/1) to give XXIII (8 mg, 57%). ¹ H NMR (CDCl₃)7.48 (m, 2H), 7.37 (m, 3H), 5.46 (s,1H), 4.36 (dd, J=11, 5 Hz, 1H), 3.68(dd, J=11, 10 Hz, 1H), 3.60 (d, J=10 Hz, 1H), 3.39 (dd, J= 10, 9 Hz,1H), 2.68 (d, J=11 Hz, 1H), 2.22 (d, J=11 Hz, 1H), 2.21(s, 1H), 2.16(ddd, J=10, 9, 5 Hz, 1H), 1.57 (s, 3H), 0.86 (s, 9H), 0.06 (s, 3H),-0.08 (s, 3H).

EXAMPLE 36 Synthesis of1,5-dideoxy-2-C-methyl-1,5-[{(phenylmethoxy)carbonyl}imino]-4,6-O-(R-phenylmethylene)-D-mannitol(XXIV)

To a solution of XXII (70 mg, 0.14 mmol) in tetrahydrofuran (5 ml),lithium aluminum hydride (23 mg, 0.57 mmol) was added. After refluxingfor 4 hr, the reaction mixture was cooled to room temperature anddiluted with ethyl acetate. After stirring for 15 min., the reaction wascarefully quenched by adding drops of 1N HCl and diluted with water. Themixture was extracted with ethyl acetate and the organic layer waswashed with water and brine. After drying (MgSO₄), the solvent wasremoved and the crude product (50 mg) was chromatographed (silica gel,hexane/ethyl acetate 1/1) to give XXIV (12 mg, 21%) ¹ H NMR (CDCl₃) 7.48(m, 2H), 7.37 (m, 8H), 5.58 (s,1H), 5.16 (d, J=12 Hz, 1H), 5.10 (d, J=12Hz, 1H), 4.77 (dd, J=12, 5 Hz, 1H), 4.60 (dd, J=12, 10 Hz, 1H), 4.28 (d,J=14 Hz, 1H), 3.93 (dd, J=10, 9 Hz, 1H), 3.50 (d, J=9 Hz, 1H), 3.23 (td,J=10, 5 Hz, 1H), 2.80 (d, J=14 Hz, 1H), 2.61 (broad s, 1H), 2.32(broads, 1H), 1.30 (s, 3H).

EXAMPLE 37

Various illustrative compounds synthesized above were tested forinhibition of visna virus in vitro in a plaque reduction assay (MethodA) or for inhibition of HIV-1 in a test which measured reduction ofcytopathogenic effect in virus-infected synctium-sensitiveLeu-3a-positive CEM cells grown in tissue culture (Method B) as follows:

Method A Cell and Virus Propagation

Sheep choroid plexus (SCP) cells were obtained from American TypeCulture Collection (ATCC) catalogue number CRL 1700 and were routinelypassaged in vitro in Dulbecco's Modified Eagles (DME) mediumsupplemented with 20% fetal bovine serum (FBS). SCP cells were passagedonce per week at a 1:2 or 1:3 split ratio. Visna was titrated by plaqueassay in six-well plates. Virus pools were stored at -70° C.

Plaque Reduction Assay

SCP cells were cultured in 6-well plates to confluence. Wells werewashed two times with serum free Minimal Essential Medium (MEM) toremove FBS. 0.2 ml of virus was added per well in MEM supplemented with4 mM glutamine and gentamycin. After 1 hour adsorption, the virus wasaspirated from each well. The appropriate concentration of each compoundin 5 ml of Medium 199 (M-199) supplemented with 2% lamb serum, 4 mMglutamine, 0.5% agarose and gentamycin was added to each well. Cultureswere incubated at 37° C. in a humidified 5% CO₂ incubator for 3-4 weeks.To terminate the test; cultures were fixed in 10% formalin, the agarremoved, the monolayers stained with 1% crystal violet and plaquescounted. Each compound concentration was run in triplicate. Controlwells (without virus) were observed for toxicity of compounds at thetermination of each test and graded morphologically from 0 to 4. 0 is notoxicity observed while 4 is total lysing of the cell monolayer.

96 Well Plate Assay

The 96 well plate assay was performed similarly to the plaque assayabove with modifications. SCP cells were seeded at 1×10⁴ cells per wellin 0.1 ml DME medium. When confluent, the wells were washed with serumfree MEM and 25 μl of virus added in M-199 supplemented with 2% lambserum. After 1 hour, 75 μL of medium containing test compound was addedto each well containing virus. After 2-3 weeks incubation the cytopathiceffect of the virus was determined by staining with a vital stain. Cellviability was measured by determining stain density using a 96 wellplate reader.

Control wells without virus were completed to determine the toxicity ofcompounds.

Method B

Tissue culture plates were incubated at 37° C. in a humidified, 5% CO₂atmosphere and observed microscopically for toxicity and/orcytopathogenic effect (CPE). At i hour prior to infection, each testarticle was prepared from the frozen stock, and a 20 μl volume of eachdilution (prepared as a 10× concentration) was added to the appropriatewells of both infected and uninfected cells.

On the 9th day post-infection, the cells in each well were resuspendedand a 100 μl sample of each cell suspension was removed for use in anMTT assay. A 20 μl volume of a 5 mg/ml solution of3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) wasadded to each 100 μl cell suspension, and the cells were incubated at37° C. in 5% CO₂ for 4 hours. During this incubation MTT ismetabolically reduced by living cells, resulting in the production of acolored formazan product. A 100 μl volume of a solution of 10% sodiumdodecyl sulfate in 0.01N hydrochloric acid was added to each sample, andthe samples were incubated overnight. The absorbance at 590 nm wasdetermined for each sample using a Molecular Devices V_(max) microplatereader. This assay detects drug-induced suppression of viral CPE, aswell as drug cytotoxicity, by measuring the generation of MTT-formazanby surviving cells.

Assays were done in 96-well tissue culture plates. CEM cells weretreated with polybrene at a concentration of 2 μg/ml, and an 80 μlvolume of cells (1×10⁴ cells) was dispensed into each well. A 100 μlvolume of each test article dilution (prepared as a 2× concentration)was added to 5 wells of cells, and the cells were incubated at 37° C.for 1 hour. A frozen culture of HIV-1, strain HTVL-III_(B), was dilutedin culture medium to a concentration of 5×10⁴ TCID₅₀ per ml, and a 20 μlvolume (containing 10³ TCID₅₀ of virus) was added to 3 of the wells foreach test article concentration. This resulted in a multiplicity ofinfection of 0.1 for the HIV-1 infected samples. A 20 μl volume ofnormal culture medium was added to the remaining wells to allowevaluation of cytotoxicity. Each plate contained 6 wells of untreated,uninfected, cell control samples and 6 wells of untreated, infected,virus control samples.

Table I, below, sets forth the results of the assay for the compoundsXVIA, XVIB and XVIC compared to the N-butyl DNJ antiviral agentdescribed in U.S. Pat. No. 4,849,430, which was used as a controlstandard, in Method B: These results are stated in terms of the ID₅₀(medium inhibitory dose) and TD₅₀ (medium toxic dose).

    ______________________________________                                        Anti HIV Activity of 2-Methyl Carbinol Analogs                                 ##STR15##                                                                    Compd. (R)    R.sub.4 ID.sub.50 (μg/ml)                                                                     TD.sub.50 (μg/ml)                         ______________________________________                                              n-Bu        H        34      >500                                       XVIA  (n-Bu)      Me      237      20% (500)                                  XVIB  [(CH.sub.2).sub.3 Ph]                                                                     Me      492      40% (500)                                  XVIC  [CH.sub.2 CH(Et).sub.2 ]                                                                  Me       6        349                                       ______________________________________                                    

EXAMPLE 38

Intermediate 2-C-methyl-4,6-O-benzylidene-1-deoxynojirimycin (XIV),prepared in Example 22, above, was tested for inhibition of HIV by theassay of Example 37 and found to have and ID₅₀ of 513 μg/ml in Method B.

The antiviral agents described herein can be used for administration toa mammalian host infected with a virus, e.g. visna virus or in vitro tothe human immunodeficiency virus, by conventional means, preferably informulations with pharmaceutically acceptable diluents and carriers.These agents can be used in the free amine form or in their salt form.Pharmaceutically acceptable salt derivatives are illustrated, forexample, by the HCl salt. The amount of the active agent to beadministered must be an effective amount, that is, an amount which ismedically beneficial but does not present toxic effects which overweighthe advantages which accompany its use. It would be expected that theadult human dosage would normally range upward from about one milligramof the active compound. The preferable route of administration is orallyin the form of capsules, tablets, syrups, elixirs and the like, althoughparenteral administration also can be used. Suitable formulations of theactive compound in pharmaceutically acceptable diluents and carriers intherapeutic dosage form can be prepared by reference to general texts inthe field such as, for example, Remington's Pharmaceutical Sciences, Ed.Arthur Osol, 16th ed., 1980, Mack Publishing Co., Easton, Pa.

Various other examples will be apparent to the person skilled in the artafter reading the present disclosure without departing from the spiritand scope of the invention. It is intended that all such other examplesbe included within the scope of the appended claims.

What is claimed is:
 1. A compound of the formula ##STR16## wherein R₃=MEM, SEM, TBDMS or CH₃, and Z is COOCH₂ Ph.
 2. A compound of claim 1 inwhich R₃ is 2-(trimethylsilyl)ethoxymethyl.
 3. A compound of claim 1 inwhich R₃ is tert-butyldimethylsilyl.
 4. A compound of claim 1 in whichR₃ is 2-methoxyethoxymethyl.
 5. A Compound of claim 1 in which R₃ isCH₃.
 6. A compound of the formula ##STR17## wherein R₃ =MEM, SEM, TBDMSor CH₃, and Z is COOCH₂ Ph.
 7. A compound of claim 6 in which R₃ is2-(trimethylsilyl)ethoxymethyl.
 8. A compound of claim 6 in which R₃ istertbutyldimethylsilyl.
 9. A compound of claim 6 in which R₃ is2-methoxyethoxymethyl.
 10. A compound of claim 6 in which R₃ is CH₃. 11.A compound of the formula ##STR18## wherein R₃ =MEM, SEM, TBDMS or CH₃,and Z is COOCH₂ Ph.
 12. A compound of claim 11 in which R₃ is2-(trimethylsilyl)ethoxymethyl.
 13. A compound of claim 11 in which R₃is tertbutyldimethylsilyl.
 14. A compound of claim 11 in which R₃ is2-methoxyethoxymethyl.
 15. A compound of claim 11 in which R₃ is CH₃.16. A compound of the formula ##STR19## wherein Z is COOCH₂ Ph.
 17. Acompound of the formula ##STR20## wherein Z is COOCH₂ Ph and R₃ is CH₃or MEM and R₄ is CH₃.
 18. A compound of the formula ##STR21## wherein Zis COOCH₂ Ph.
 19. A compound of the formula ##STR22##
 20. A compound ofthe formula ##STR23## wherein R₃ =H or SiMe₂ (t-Bu), and Z is COOCH₂ Ph.21. A compound of claim 20 in which R₃ is H.
 22. A compound of claim 20in which R₃ is SiMe₂ (t-Bu).
 23. A compound of the formula ##STR24##wherein R₃ =H or SiMe₂ (t-Bu), and Z is COOCH₂ Ph.
 24. A compound ofclaim 23 in which R₃ is H.
 25. A compound of claim 23 in which R₃ isSiMe₂ (t-Bu).
 26. A compound selected from the group consisting of a2-epoxide derivative of 1-deoxynojirimycin having the formula ##STR25##wherein Z is COOCH₂ Ph.
 27. A compound selected from the groupconsisting of 2-methyl carbinol derivatives having the formula ##STR26##wherein Z is COOCH₂ Ph.